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Students observe light passing through water and colored liquids to understand how the scattering of light produces blue skies and red sunsets.

Learning Objectives

Students explore how light is scattered in Earth's atmosphere, making the sky look blue and orange at sunset/sunrise.

Students make and describe observations.

Time

Educational Standards

Next Generation Science Standards

PE:4-PS3-2. Make observations to provide evidence that energy can be transferred from place to place by sound, light, heat, and electric currents.

DCI:PS3.B.Conservation of Energy and EnergyTransfer, PS4.A. Wave Properties

SEP: Developing and Using Models

CCC: Cause and Effect, Patterns

Materials

For each group of four:

Tall clear drinking glass or clear soda bottle

Water

Whole milk (about a cup or a small carton)

Drinking straws

Flashlight

Writing paper and pencil

Optional: Paint samples of various blue/orange/red colors to compare with the color of the scattered light

Directions

1. Darken the room by closing shades and turning off the lights. Have student groups shine a flashlight at the top of a tall glass of water.

2. Ask students to describe in writing the color of the light coming from the flashlight, the color of light as it travels through the glass, and the color of the liquid at the bottom of the glass. (Put a sheet of white paper on the far side to avoid seeing colors through the glass.)

3. Turn on the classroom lights and instruct student groups to fill their straw with about an inch of milk, add it to the glass of water, and mix. (If you are using a soda bottle, you will need to use more milk.)

4. Turn off the lights and again instruct student groups to shine a flashlight at the top of the glass of water.

5. Ask students to describe in writing the color of the light coming from the flashlight, the color of light as it travels through the glass, and the color of the liquid from the far side of the glass.

6. If your students can't see any change in color, instruct them to add a few more drops of milk to the mixture and try again. The light will look blue where it has traveled through milky water. At the other end of the container, where the light has traveled through most of the milky water, the light appears yellow, orange, or red.

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Background

Sunlight, or visible light, is composed of the rainbow colors: red, orange, yellow, green, blue, and violet. Visible light is a part of the electromagnetic spectrum and carries energy in waves. Colors towards the red end of the spectrum have longer wavelengths and colors near the violet end of the spectrum have shorter wavelengths. Light waves can transfer energy when they interact with matter.

The molecules and other particles in Earth's atmosphere scatter (re-emit) some wavelengths of light more easily than others. The shorter wavelengths, such as violet and blue are the most likely to be scattered. The sky is blue because our eyes are not very sensitive to violet light.

When the Sun is low in the sky, sunlight travels through a much greater thickness of atmosphere than it does when it is overhead. Over this greater distance, more wavelengths of light are scattered including longer wavelengths like green, yellow, and orange. Only the red light comes through to your eyes; so, the setting Sun often looks red.

In this activity, the suspended particles of milk scatter light like molecules and other particles in Earth's atmosphere. Where the light has only traveled through the top layer of water, it appears light blue. Where it has traveled through most of the water, it appears yellow, orange, or red. If you add too much milk to the water, the glass will have a yellowish hue just like the atmosphere on a smoggy day.

Credits

This version of Blue Skies and Red Sunsets is used at the NCAR Mesa Lab for school field trips.

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Students observe light passing through water and colored liquids to understand how the scattering of light produces blue skies and red sunsets. Students explore how light is scattered in Earth's atmosphere, making the sky look blue and orange at sunset/sunrise. Students make and describe observations. PE:4-PS3-2.

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The King's Centre for Visualization in Science

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The King's Centre for Visualization in Science

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The King's Centre for Visualization in Science is a research centre of The King's University, Edmonton, Alberta, Canada committed to improving the global public understanding of science through research and the creation and dissemination of peer-reviewed interactive electronic learning tools to see and understand science.

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Using the Concept Builder

The Spectrum Concept Builder is shown in the iFrame below. There is a small hot spot in the top-left corner. Clicking/tapping the hot spot opens the Concept Builder in full-screen mode. Use the Escape key on a keyboard (or comparable method) to exit from full-screen mode.

There is a second hot-spot in the lower-right corner of the iFrame. Dragging this hot-spot allows you to change the size of iFrame to whatever dimensions you prefer.

Using the Concept Builder

This Concept Builder will open in a separate browser window on your device. Click the Launch Tool button to open the Concept Builder. Close the window to return to this page.

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Each interactive concept-builder presents learners with carefully crafted questions that target various aspects of a discrete concept. There are typically multiple levels of difficulty and an effort to track learner progress at each level. Question-specific help is provided for the struggling learner; such help consists of short explanations of how to approach the situation.

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Chemistry

What?!? Chemistry? At The Physics Classroom?

Yes. Why not? We're not breaking any laws ... it's perfectly legal. The Concept Builders you see below are  interactive questioning modules that present learners with carefully crafted questions that target various aspects of a concept. If you're a frequent visitor to our website, you likely have used some of our Physics Concept Builders. Each Concept Builder focuses the learner's attention upon a discrete learning outcome. Questions target that outcome from a variety of angles using multiple difficulty levels or varying activities. If you're a chemistry teacher visiting our website for the first time, then welcome! We invite you to give one of our Chemistry Concept Builders a try and let us know what you think.

Chemistry Topics to Explore

Quick Links

Chemistry Fundamentals

Measurement and Numbers

Learning Goal: To identify common units of measurement, to read an instrument to the proper number of significant digits, and to convert between standard and scientific notation.

Significant Digits and Measurement

Learning Goal: To understand the concept of significant digits and to use such understanding to make and process such measurements made from lab equipment.

Metric System

Learning Goal: To generate a comfort with the use of the metric system in order to convert simple quantities and compare given quantities.

Metric Estimation

Learning Goal: To use an understanding of metric units of length, mass, and volume to identify a best estimate of such quantities for a variety of common objects.

Metric Conversions

Learning Goal: To use an understanding of metric units and their Greek prefixes to perform conversions between a variety of metric units.

Properties of Matter

Classification of Matter

Learning Goal: To identify samples of matter as being pure substances or mixtures (homogenous or heterogeneous) and to distinguish between elements and compounds.

Name That Element

Learning Goal: To express a comfort with the organization of the periodic table, including concepts related to family names, periods, groups, metals, nonmetals, metalloids, atomic number, and atomic mass.

Chemical vs. Physical Properties

Learning Goal: To identify a stated property as being either a chemical or a physical property.

Density Ranking Tasks

Learning Goal: To rank the density of three samples of matter based on information about the massiveness of its particles and the amount of space they take up.

Metals, Nonmetals, and Metalloids

Learning Goal: To identify the difference between metals, nonmetals, and metalloids and to be able to place an element into one of these categories.

Particles .. Words .. Formulas

Learning Goal: To associate the particle representation of a sample of matter with the proper verbal description and formulas.

Subatomic Particles

Learning Goal: To determine the atomic number, mass number, # of protons, # of neutrons, and the # of electrons for an atom or an ion of an element from an isotope symbol.

Isotopes

Learning Goal: To demonstrate understanding of the composition of an atom by constructing the isotopic symbol from information regarding the number of protons, neutrons, and electrons.

Describing Chemical Change

Names to Formulas 1

Learning Goal: To use an understanding of formula writing to identify incorrectly written formulas.  (Includes binary ionic compounds only.)

Names to Formulas 2

Learning Goal: To use an understanding of formula writing to identify incorrectly written formulas.  (Includes binary molecular compounds, binary ionic compounds, and compounds containing polyatomic ions.)

Formulas and Atom Counting

Learning Goal: To identify the number of atoms of each element represented by a set of simple or complex formulas.

Balancing Chemical Equations

Learning Goal: To be able to use coefficients and an atom count to balance a chemical equation.

Chemical Reaction Types

Learning Goal: To be able to categorize chemical reactions based on their reaction type - such as synthesis, decomposition, combustion, single replacement, and double replacement.

Writing Balanced Chemical Equations

Learning Goal: To combine an understanding of reaction types, formula writing, and equation balancing in order to write a balanced chemical equation.

Precipitation Reactions

Learning Goal: To predict the precipitate that is produced when two aqueous solutions of ionic compounds are mixed and to represent the precipitation reaction by a net ionic equation.

Quantifying Chemical Change

Molar Mass

Learning Goal: To determine the molar mass if given the chemical formula of a compound.

Mole Conversions

Learning Goal: To mathematically relate the the number of moles of a compound to the number of molecules and to the mass in grams.

Stoichiometry: Relationships

Learning Goal: To use the coefficients of a balanced chemical equation and the molar masses of reactants and products to relate the quantities of reactants and products involved in a reaction.

Atomic and Molecular Models

Atomic Models

Learning Goal:  To identify the connection between experimental findings, conclusions, and models that are associated with atomic structure.

Subatomic Particles

Learning Goal: To determine the atomic number, mass number, # of protons, # of neutrons, and the # of electrons for an atom or an ion of an element from an isotope symbol.

Isotopes

Learning Goal: To demonstrate understanding of the composition of an atom by constructing the isotopic symbol from information regarding the number of protons, neutrons, and electrons.

Line Spectra

Learning Goal:  To relate the color of lines in a line spectra of an element to the energy level transitions that are occurring.

Quantum Mechanics

Learning Goal:  To identify the meaning of the four quantum numbers, the rules governing allowed and non-allowed quantum number values, and the characteristics of atomic orbitals.

Complete Electron Configurations

Learning Goal: To identify the complete electron configuration for a neutral atom or of an ion of any given element.

Periodic Table Battleship

Learning Goal: To associate an electron configuration with a location of an element on the periodic table.

Periodic Trends

Learning Goal: To order elements based on the values of periodic properties such as atomic radius, ionization energy, and electronegativity.

Ionic Bonding

Learning Goal: To identify the types of elements that undergo ionic bonding and to be able to describe the process that takes place when two elements form ionic bonds.

Bond Polarity

Learning Goal: To use electronegativity values to identify a bond as being polar or non-polar … and if polar, to identify the direction of the dipole moment vector.

Lewis Structures

Learning Goal:  To identify correct and incorrect Lewis electron dot structures when given the formulas of molecular compounds.

Valence Shell Electron Pair Repulsion Theory

Learning Goal:  To identify the Lewis electron dot diagram and the molecular shape of a variety of covalently-bonded molecules.

Molecular Polarity

Learning Goal:  To use electronegativity values, a Lewis structure, and an understanding of molecular shape to identify a molecule as being polar or non-polar.

Thermal Chemistry and Thermodynamics

Measuring the Quantity of Heat

Learning Goal:  To use the equation Q = m•C•∆T to relate the heat released to the surroundings to the mass and temperature change of the surroundings and to the enthalpy change of the system.

Which One Doesn't Belong? - Energy and Chemical Reactions

Learning Goal:  To interpret various representations of a thermochemical reaction and to identify which one is not consistent with the others.

Enthalpy Change

Learning Goal: To use calorimetry data and the amount of reactant to determine the enthalpy change for a stated reaction and to include the energy term on the proper side of a thermochemical equation.

Thermal Stoichiometry

Learning Goal: To use a thermochemical equation to relate the mass and the moles of reactant to the amount of energy released in a combustion reaction.

Hess's Law

Learning Goal: To apply Hess’s Law in order to determine the ∆H of a reaction if given the ∆H of two or more related reactions.

Heat of Formation

Learning Goal: To identify the meaning of heat of formation and to use heats of formation values for reactants and products to determine the enthalpy change of a reaction.

Entropy

Learning Goal: To compare the entropy of two different states and to identify the entropy change of a process as being either a positive or a negative change.

Spontaneity and Driving Forces

Learning Goal: To use knowledge of the ∆H and ∆S values for a reaction in order to predict whether it is spontaneous or not.

Gibb's Free Energy

Learning Goal: To use the Gibb’s Free Energy equation to calculate a free energy change (∆G) from ∆H and ∆S values at various temperatures and to make judgement regarding the spontaneity of the reaction.

Solids, Liquids, and Gases

States of Matter

Learning Goal:  To describe the three most common states of matter and to describe the state transitions that take place.

Pressure Concepts

Learning Goal:  To be able to explain at the particle level the factors that effect gas pressure, to compare values of pressure expressed in different units, and to use manometer information to determine the pressure of a gas.

Pressure and Temperature

Learning Goal:  To use an understanding of the pressure-temperature relationship in order to predict how the value of pressure changes with changing temperature.

Volume and Temperature

Learning Goal:  To use an understanding of the volume-temperature relationship in order to predict how the value of volume changes with changing temperature.

Pressure and Volume

Learning Goal:  To use an understanding of the pressure-volume relationship in order to predict how the pressure of a gas changes with varying volume.

Acids, Bases, and Solutions

Dissociation

Learning Goal:  To be able to write the equation for the dissociation of an ionic compound in water and to use the equation to determine ion concentrations if given the concentration of the ionic compound.

Molarity Ranking Tasks

Learning Goal:  To rank the relative molarity of three aqueous solutions based on the amount of solute, the amount of solvent, and the identity of the solute.

Molarity Calculations

Learning Goal:  To use molarity definition to calculate the molarity of a solution from knowledge of the amount of solute (in grams or moles) and the volume of the solution.

Which One Doesn't Belong? - Acid-Base Properties

Learning Goal:  To analyze a variety of properties of acids and bases in order to identify which property is not like the others.

Bronsted-Lowry Model of Acids and Bases

Learning Goal:  To use the Bronsted-Lowry model to determine the products of the dissociation of an acid or a base when dissolved in water.

pH and pOH

Learning Goal:  To mathematically relate the pH, pOH, [H₃O⁺], and [OH⁻] for aqueous solutions of acids and bases.

Equilibrium and Kinetics

Collision Model of Reaction Rates

Learning Goal:  To identify the variables that affect reaction rate and to explain the effects using the Collision Model of reaction rates.

The Equilibrium Concept

Learning Goal:  To identify the conditions that exist at equilibrium, to comprehend the meaning of he equilibrium concept (K), and to use the K value to predict the direction a reaction proceeds to reach equilibrium.

Equilibrium Constant Expression

Learning Goal:  To use the Law of Mass Action in order to identify the equilibrium constant expression for a given chemical equation.

Equilibrium Calculations

Learning Goal:  To use an equlibrium constant expression to determine the equilibrium constant value or the value of the concentration of a reactant or product at equilibrium.

Equilibrium ICE Tables

Learning Goal:  To learn how to set up an ICE table and then use it to relate initial concentrations of reactants and products to the equilibrium constant.

LeChatelier's Principle

Learning Goal:  To identify the effect that a stress has upon a system that is at equilibrium.

Electrochemistry

Oxidation States

Learning Goal: To identify the oxidation state of elements in various substances.

Oxidation-Reduction

Learning Goal:  To use oxidation numbers to determine the elements being oxidized and reduced in an oxidation-reduction reaction and to identify the oxidizing and reducing agents.

Galvanic Cells

Learning Goal:  To create a galvanic cell diagram, identifying the anode and cathode, the direction of electron flow and positive and negative ion flow, and identifying the half equations occurring in each half-cell.

Reduction Potential

Learning Goal:  To interpret a standard reduction potential table in order to make judgements about the strength and capability of oxidizing and reducing agents.

Cell Voltage

Learning Goal:  To use the Reduction Potential Table to determine the cell voltage of a galvanic cell.

Nuclear Chemistry

Nuclear Decay

Learning Goal:  To identify the various forms of nuclear decay and the effect of each upon the atomic number and mass number of an isotope.

We started adding Chemistry Concept Builders in September, 2018. As of this writing (early February, 2022), we have 66 Chemistry Concept Builders. We still have many more planned.

This might be The Physics Classroom, but Chemistry is still a legal operation on this site. So enjoy our Chem Gems.

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Each interactive concept-builder presents learners with carefully crafted questions that target various aspects of a discrete concept. There are typically multiple levels of difficulty and an effort to track learner progress at each level. Question-specific help is provided for the struggling learne…

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Light and Color

NOTE: The five Color Interactives below require WebGL - a Javascript API that is built into most modern browsers including those on mobile devices such as phones and tablets. Older browsers may include WebGL as a non-default feature that can be enabled. If the Interactive fails to load, it may be time to update your browser or to enable WebGL.

Electromagnetic Spectrum Infographic

For some time, the public domain infographic from 1944 that was rescued from the trash and made popular by Lawrence Livermore National Laboratories has fascinated science teachers of all disciplines. And now The Physics Classroom has made an Interactive version that will allow students to explore its many layers of information and glean an understanding of electromagnetic waves as made popular by this timeless piece of science and art.
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RGB Color Addition

Turn on the colored spotlights. Adjust their intensity. And learn some principles of color addition. View a computer image in terms of its red, green, and blue color components. Even upload your own image and view its RGB components.

Now available with a Concept Checker.
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Painting with CMY

The football coach wants new uniforms and you're in charge! Oddly enough the uniform supplier wants you to place the order by indicating what colors of pigments should be imparted to the fabric. It's time for you to learn about colored pigments and the rules of color subtraction. Open our Interactive and start painting. You'll learn the rules in no time and we'll even clean the mess up for you.

Now available with a Concept Checker.

Colored Shadows

Did you know that the color appearance of an object can be changed by changing the color of light that shines on it? It can! And now you can find out how by using our Colored Shadows Interactive. You can explore the color appearance of a person and of the shadows creating by that person on a white screen with our Colored Shadows simulation.

Filtering Away

A color filter is a transparent film that absorbs a range of wavelengths of light. Looking at the world through a color filter will change the color appearance of objects. And lucky for you this can be done for FREE ... right here at The Physics Classroom. Take a peek, free of charge, at a set of six colored circles as seen through one of six filters.

Now available with a Concept Checker.

Colored Filters

Perhaps you have looked at the world through sunglasses that have a colored tint. Exactly how do they work? We can answer this question as we would many questions in life. They work because of physics. And in this simulation, you will probe the answer by learning about color filters. You won't need any expensive lasers; we'll provide those for you. You won't even need any colored-tinted sunglasses; we got you covered there too. All you need is an inquisitive mind and our Colored FIlters Interactive.

Stage Lighting

The curtains open, the theater lights dim, the actors enter the stage, and you begin enjoying the school play. And then all of sudden, the stage lights change colors and the actors appear ... different. The yellow shirt of your favorite actor turns green, leaving you wondering exactly what is going on. Of course, you've just witnessed Physics! And now its time to let all that wondering about colored spotlights and the appearance of actors on the stage turn to understanding. So open this Stage Lighting Interactive and start finding some answers.

Now available with a Concept Checker.

Viewed in Another Light

Turn on the white light and look at the color of five M&Ms. This is their color in white light. But what if you can change the light? Will a red M&M always look red? This simulation - more of a collection of photos will allow you to investigate the color appearance of five M&Ms when viewed under various colors of light.
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Young's Experiment

Did you know that light behaves as a wave and has a wavelength? That's right, it does. In fact, the wavelength of the light that the human eye detects is less than one-millionth of a meter in length. That's pretty small. And amazingly enough, scientists can make
a few simple measurements and calculate its wavelength. All that is needed is a laser, a slide with a couple of closely-spaced slits, and a screen. Don't have the materials handy? That's OK because we have them on loan at our Physics Interactive titled Young's Experiment. So tap on that link and let's get started.

Now available with Task Tracker compatibility. Learn more.

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Physics Simulations: Light Waves and Color

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This collection of interactive simulations allow learners of Physics to explore core physics concepts by altering variables and observing the results. Our Light Waves and Color section includes several simulations exploring the nature of electromagnetic waves and visible light waves.

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These resources are designed for self study and contain tutorials and self assessment quizzes on key aspects of first year chemistry. Some require the 'Flash' plugin to be installed and enabled on your computer - for help with this, please consult the Adobe help pages.

Atomic orbitals and electronic configurations: relationship between the quantum numbers and orbital shapes.

Atomic symbols: how to read atomic symbols to extract the number of electrons, protons and neutrons for atoms, cations and anions.

Balancing chemical equations: how to write and then balance chemical equations.

Cell potentials: how to calculate standard cell potentials from half cell potentials.

Common anion flip card game for mobiles: game to help learn and remember common anions on your smart phone.

Common cation flip card game for mobiles: game to help learn and remember common anions on your smart phone.

Common anion and cation flip card game for mobiles: game to help learn and remember common anions on your smart phone.

Coordination numbers: molecules, complexes, metallic solids and ionic compounds.

The Elements: games and quizzes to help familiarity with the Periodic Table.

Electronegativity and bonding: Periodic trends in electronegativity and how to use it to predict bonding type and partial charges.

Empirical formula calculator: work out the empirical formula of a compoound from its elements and their percentage masses.

Flashcards: flashcards on a variety of topics including common organic functional groups and common cations and anions.

Functional group flip card game for mobiles: game to help learn and remember common organic functional groups on your smart phone.

Galvanic cells: understanding what is going on when a cell is operating, including the direction of electron and ion flow.

Galvanic and electrolytic cells: understanding what is going on when these electrochemical cells are operating, including the direction of electron and ion flow.

Gas Laws: using the ideal gas law and choosing the right value of the gas constant, R.

Heat capacity: the difference between heat and temperature and how to convert between them using heat capacities.

Inorganic nomenclature: how to write the formula and names of inorganic compounds.

Nomenclature for complexes: how to write the formulae and names of transition metal complexes following the updated IUPAC rules and work out d-configurations.

Le Châtelier's principle: how to predict the direction in which an equilibrium will shift when a change is applied.

Lewis structures: how to draw Lewis structures for molecules obeying and disobeying the octet rule.

Lewis structure maker: build interactive Lewis structures containing multiple bonds and lone pairs for molecules obeying and disobeying the octet rule.

Limiting reagents: how to work out which reagent is the limiting reagent in a reaction, and how much product will result.

MO energies: study the effect of orbital overlap and energies on bonding and the energy and form of molecular orbitals.

MO diagrams: build interactive molecular orbital diagrams for diatomic molecules.

Molar mass calculator: simply enter a formula and calculate the molar mass, the number of moles in 1 g and the percentage by mass of each element.

Molar mass calculator for mobiles: simply enter a formula and calculate the molar mass, the number of moles in 1 g and the percentage by mass of each element on your smart phone.

Moles: introduction to the concept of the mole and help with converting between mass, molar mass and moles.

Mole calculations: revision tutorial on mole problems.

Naming organic compounds: tutorial and self test quizzes on organic nomenclature.

Naming alcohols, amines and halides: tutorial and self test quizzes on using the labels primary, secondary, tertiary and quaternary and on naming alcohols, amines and halides.

Naming and identifying carbonyl containing compounds: tutorial and self test quizzes on aldehydes, ketones and carboxylic acid derivatives.

Organic reactions and acidity of organic molecules: tutorial and self test quizzes on the acidity of organic molecules and types of organic reactions.

Organic isomers: tutorial on isomerism in organic chemistry, including chirality.

Organic isomers and chirality: assigning priorities and absolute configurations in chiral molecules.

Organic structure determination: tutorial and self test quizzes on how spectroscopy is used to determine the structures of organic molecules.

Organic structures: tutorial on how organic structures are drawn as condensed structural formulae and as stick structures and how to convert between them.

Organic synthesis and retrosynthesis: tutorial and self test quizzes on strategies for designing synthetic routes.

Oxidation numbers: how to work out the oxidation number of an element in a molecule or ion.

Predicting nuclear decay: how to predict whether a nucleus is radioactive and whether it will undergo β⁺, β⁻ or α decay.

Properties of waves: characteristic properties of waves and electromagnetic radiation.

pH of strong acids and bases - how to calculate pH from the concentration of a strong acid or base

Radioactivity calculations: calculating activities and performing carbon dating equations.

Radioactive decay equations: how to write and balance nuclear equations for β⁺, β⁻ or α decay.

Redox reactions: how to write redox equations by combining half cell reactions.

Shape of the Periodic Table: relationship between chemical properties of the elements and electronic configurations and the Periodic Table.

Shape and molecular polarity: the relationship between the shape of a molecule and its polariy.

Significant figures: how to work out the number of significant figures that can be justified when adding, dividing, multiplying and subtracting measurements.

Solutions: how to work out concentrations and how to convert between molarity, moles and volume.

Solubility: introduction to solubility and how to write equations and solve equilibria problems for solutions of ionic salts.

Common crystal structures: 3D, rotatable and interactive versions of the commonest crystal types

Close packing: buidling solids based on repeating ABABABAB... and ABCABCABC... layers

Packing and unit cells: relationship between the cubic and hexagonal close packed layers and their unit cells

Vibrations: interactive animations of molecular vibrations

VSEPR molecular shapes (by number of electron pairs): shapes for main group molecules and ions with 2-7 sets of electron pairs.

VSEPR molecular shapes (by formula): shapes for main group molecules and ions with 2-7 bonds.

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ichem tutorials and self learning quizzes

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iChem tutorials and self learning quizzes

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These resources are designed for self study and contain tutorials and self assessment quizzes on key aspects of first year chemistry. Some require the 'Flash' plugin to be installed and enabled on your computer - for help with this, please consult the Adobe help pages.

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Using the Concept Builder

The Complete Electron Configurations Concept Builder is shown in the iFrame below. There is a small hot spot in the top-left corner. Clicking/tapping the hot spot opens the Concept Builder in full-screen mode. Use the Escape key on a keyboard (or comparable method) to exit from full-screen mode.

There is a second hot-spot in the lower-right corner of the iFrame. Dragging this hot-spot allows you to change the size of iFrame to whatever dimensions you prefer.

Using the Concept Builder

This Concept Builder will open in a separate browser window on your device. Click the Launch Tool button to open the Concept Builder. Close the window to return to this page.

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Complete Electron Configurations Concept Builder

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Each interactive concept-builder presents learners with carefully crafted questions that target various aspects of a discrete concept. There are typically multiple levels of difficulty and an effort to track learner progress at each level. Question-specific help is provided for the struggling learner; such help consists of short explanations of how to approach the situation.

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Many of the basic concepts that you should already know from your high school chemistry course. A brief introduction to what this course is about.

One of the 3 basics forms of matter, gases are an important part of chemistry. Their physical behavior can be modeled and described mathematically.

The atom is the basic building block of chemistry. Understanding the structure and energetics of the atom is a key to understanding more complicated particles such as molecules.

A molecule is a collection of atoms held together via chemical bonds. An understanding of bonding allows a more thorough knowledge of molecular behavior.

Intermolecular forces govern the physical properties of matter. Gases, liquids, and solids have specific properties that are unique to each state.

All of our observable science is governed by thermodynamics - which is a study of the energy requirements and demands of matter interaction.

Equilibria of the physical states of matter. Thermodynamics of the dissolved state (aqueous) and solubility equilibria.

General equilibrium concepts. Mass action expression. Equilibrium constants and how to create and use a RICE table to solve equilibrium problems.

Acid/Base theory and equilibria. Weak acids and bases, pH, buffers, titrations, and indicators.

Saturated solutions and solubility equilibria.

Chemical kinetics - the rates of chemical reactions. Reaction mechanisms. Reaction coordinates.

Reduction / oxidation or redox reactions. Electrochemical cells. Standard Electrical Potentials. Batteries.

Nuclear reactions and their processes.

A simple introduction to organic chemistry: nomenclature, functional groups, and some reaction types.

An overview of some inorganic chemistry including complexation.

Chapters 2 and 5 combined into one "chapter". Intermolecular forces govern the physical properties of matter. Gases, liquids, and solids have specific properties that are unique to each state.

Videos of different lab experiments performed by Dr. Laude.

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Many of the basic concepts that you should already know from your high school chemistry course. A brief introduction to what this course is about. One of the 3 basics forms of matter, gases are an important part of chemistry. Their physical behavior can be modeled and described mathematically.

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Every winter thousands of tourists head north hoping to catch a glimpse the luminous auroras dancing in the sky. In this episode of Reactions, we're sharing tips on how to increase your chances of seeing one and breaking down the chemistry behind the colors of this awe-inspiring wonder.

Aired: 06/03/19

Rating: NR

From:

Problems Playing Video? Report a Problem |

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Reactions | What Causes the Northern Lights? | Season 2

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Every winter thousands of tourists head north hoping to catch a glimpse the luminous auroras dancing in the sky. In this episode of Reactions, we're sharing tips on how to increase your chances of seeing one and breaking down the chemistry behind the colors of this awe-inspiring wonder.

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Science News Explores publishes news from all fields of science for students from middle school and up, with resources for parents and educators.

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Careers & the Chemical Sciences - American Chemical Society

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What can you do with a chemistry degree? Or changing career direction? Explore over 40 fields in the chemical sciences. Learn what chemists do in different roles.

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Science Worksheets, Flashcards & Diagrams | STEM Sheets

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Customizable and printable science worksheets, flashcards, and diagrams. All resources are free and downloadable as a custom PDF.

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Cool Symbols & Cool Fonts - Symbols, Emoji & Fonts

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Cool Symbols & Cool Fonts is a symbol & picture text collection that helps you get Facebook symbols, fancy letters, special characters, special symbols... right in a web browser, such as math symbol, PI symbol, infinity symbol, copyright symbol, TM symbol, heart symbol,... It also provides an extensive list of emoticons, emojis, symbols & smiley faces that can be used on Facebook, Twitter, Instagram.

This Symbols & Picture Text collection provides fancy symbols, alt codes, cursive letters, text symbols, emoji symbols, special symbols, aesthetic symbols, text picture, text emoticons, keyboard symbols, fb symbols, cute symbols, cent symbols, cent sign, alt codes, bullet point, fonts for Instagram, Facebook, Twitter, ...

Copy and paste symbols with this cool symbol picker tool, which help easily get Facebook symbols, Instagram symbols, Twitter symbols, emoji, emoticon text & text art. Just click on a symbol, an emoji or a text art to copy it to the clipboard. Please also also check out our font keyboard to help users easily get fonts right at the phone keyboard at Font Keyboard iOS app and Font Keyboard Android app. Besides, we also have the Font Generator iOS app and Font Generator Android app.

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Cool Symbols & Cool Fonts - Symbols, Emoji & Fonts

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Cool Symbols & Cool Fonts is a symbol & picture text collection that helps you get Facebook symbols, fancy letters, special characters, special symbols... right in a web browser, such as math symbol, PI symbol, infinity symbol, copyright symbol, TM symbol, heart symbol,...

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Pressure Concepts - Question-Specific Help

The Pressure Concepts Concept Builder provides learners an opportunity to investigate three ideas related to gas pressure. There are a total of 36 questions organized into 14 Question Groups and spread across three different activities. In the first activity - A versus B - learners investigate the causes of gas pressure from the perspective of individual particles. The effect of four important variables - number of particles, speed of particles, mass of particles, and size of container - upon the gas pressure are explored. In the second activity - Pressure Units - learners compare the relative magnitude of three different pressure values. The values are expressed in different units so that the learner must express some comfort with the relative size of each unit. In the third activity - Manometers - learners use manometer information to determine the pressure of a sample of gas. Question-specific help is provided for each of the 14 Question Groups. The built-in score-keeping makes this Concept Builder a perfect candidate for a classroom activity.

Users are encouraged to open the Concept Builder and explore. There is no need for an activity sheet for this Concept Builder. However, the 18 different groups of questions can be printed. View Questions.

Learners and Instructors may also be interested in viewing the accompanying Notes page. Technical information, teaching suggestions, and related resources that complement this Concept Builder are provided on the Notes page. View Notes.

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The Pressure Concepts Concept Builder presents learners with an interactive exploration of gas pressure - the particle explanations of why there is pressure and the variables that affect it, an investigation of how the units atm (atmospheres), psi (pounds per square inch), and mm Hg (millimeters of mercury) compare to one another, and a study of how manometers are used to indicate the pressure of a sample of gas.

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Blood is red, and a surgeon will tell you our veins too are red, they only look blue when we see them through our skin. But why?

The answer depends on a number of things, including how your eyes perceive colour, how light behaves when it contacts your body, and the special properties of blood.

Light travels in peaks and troughs. And the distance between each trough is called a wavelength.

Different colours of light have waves of different lengths. Red light has a long wavelength (about 700 nanometres), violet light has a short wavelength (about 400 nanometres), and the rest of the spectrum is spread out in between.

We see something as a particular colour when light of that colour hits our eyes - either directly from a light source or reflected from a surface.

To understand what colour our veins appear, we need to think about what happens to different wavelengths of light when they hit our skin, how far they can travel through our skin, and what happens when they get to our veins.

The light that hits our skin during the day is basically white, which is a mixture of all the visible wavelengths.

But to explain why our veins look blue, we will look at just the red and blue ends of the spectrum.

Red light has a long wavelength - and this means it is less likely to be deflected by materials and can more easily travel through.

Red light can travel pretty well through the skin and body tissues, reaching up to 5-10 millimetres below the skin, which is where many veins are.

When it gets to the veins, the red light is absorbed by the haemoglobin (the protein that makes our blood red).

You can demonstrate this to yourself. If you shine a red light on your arm, you will see some red light reflected back, and dark lines where the veins are, as the red light is absorbed by the haemoglobin.

This phenomenon is actually used to help medical personnel find veins to take blood - by shining red, and sometimes infrared (which is an even longer wavelength) light on the arm.

Blue light has a short wavelength (about 475 nanometres), and is scattered or deflected much more easily than red light.

Because it's easily scattered it doesn't penetrate so far into the skin (only a fraction of a millimetre). When blue light hits the skin, it's mostly deflected back.

If you shine a blue light on your skin, what you see is basically blue skin, and veins are hard to find. You may have seen blue light used in spaces such as public bathrooms to discourage intravenous drug use.

We asked you to leave your thoughts on the colour of veins in the comments below.

Blue lighting makes it harder to find veins, which is why it's used to discourage intravenous drug use.(
Wikimedia Commons: JIP, CC BY-SA 3.0
)

So, now imagine the red light and the blue light shining on your skin at once, as happens when you are under white light.

You will have a mixture of red, blue and other colours reflected back where there are no veins. Where there are veins, you will see relatively less red, and relatively more blue compared to the surrounding skin.

This means your veins will appear blue compared to the rest of your skin.

Shorter wavelength blue light reflects back to us, making veins appear blue.(
Supplied: The Conversation, CC BY-ND
)

Interestingly, the effect varies depending on how deep the vein is, and also on how thick the vein is. Very narrow veins close to the surface, such as the capillary bed, will not appear blue.

Blue veins appear more prominent in very pale skinned people, and this may have given rise to the expression "blue blood" for European nobility in the 19th century.

These people were untanned from manual labour, and so their veins appeared blue under the skin.
With thanks to Science Writer at the Australian Red Cross Blood Service Alison Gould. David Irving is an adjunct professor at the University of Technology Sydney. Originally published in The Conversation

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Why our veins look blue when our blood is red

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Blood is red, and a surgeon will tell you our veins too are red, they only look blue when we see them through our skin. But why? The answer depends on a number of things, including how your eyes perceive colour, how light behaves when it contacts your body, and the special properties of blood.

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The delayed 2020 Olympics are currently taking place in Tokyo, and setting a number of firsts. Obviously, it's the first Olympics to take place without a public audience in the stadiums to watch the events. However, it's also the first Olympics at which the medals are made entirely from recycled metals. This graphic takes a [...]

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The delayed 2020 Olympics are currently taking place in Tokyo, and setting a number of firsts. Obviously, it's the first Olympics to take place without a public audience in the stadiums to watch the events. However, it's also the first Olympics at which the medals are made entirely from recycled metals.

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Standard atomic weights are the best estimates by IUPAC of atomic weights that are found in normal materials, which are terrestrial materials that are reasonably possible sources for elements and their compounds in commerce, industry, or science. They are determined using all stable isotopes and selected radioactive isotopes (having relatively long half-lives and characteristic terrestrial isotopic compositions). Isotopes are considered stable (non-radioactive) if evidence for radioactive decay has not been detected experimentally.

Element has two or more isotopes that are used to determine its atomic weight. The isotopic abundances and atomic weights vary in normal materials. These variations are well known, and the standard atomic weight is given as lower and upper bounds within square brackets, [ ].

Element has two ore more isotopes that are used to determine its standard atomic weight. The isotopic abundance and atomic weights vary in normal materials, but upper and lower bounds of the standard atomic weight have not been assigned by IUPAC or the variations may be too small to affect the standard atomic weight value significantly. Thus, the standard atomic weight is given as a single value with an uncertainty that includes both measurement uncertainty and uncertainty due to isotopic abundance variations.

Element has only one isotope that is used to determine its standard atomic weight. Thus, the standard atomic weight is invariant and is given as a single value with an IUPAC evaluated uncertainty.

Element has no standard atomic weight because all of its isotopes are radioactive and, in normal materials, no isotope occurs with a characteristic isotopic abundance from which a standard atomic weight can be determined.

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Standard atomic weights are the best estimates by IUPAC of atomic weights that are found in normal materials, which are terrestrial materials that are reasonably possible sources for elements and their compounds in commerce, industry, or science. They are determined using all stable isotopes and selected radioactive isotopes (having relatively long half-lives and characteristic terrestrial isotopic compositions).

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Common Online Data Analysis Platform (CODAP) - CODAP

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Earth's atmosphere is where most of our weather comes from! Learn more about how this jacket of gases forms clouds, rainbows and more!

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ScienceCasts: The Coolest Spot in the Universe

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This bingo card has a free space and 34 words: Li, Valence Ar, S, Mg, Valence Na, Sc, Valence Al, Valence Rb, Valence S, Be, Valence Cl, Ti, Valence Ga, Na, Valence Cs, C, P, Valence Sr, Cl, Si, F, B, O, Al, N, Ne, Valence Si, Valence Mg, Br, Fe, K, As, Ni and Valence As.

More like this:

Electron Configuration Bingo | Chemical Bingo | Name That Element | Periodic Table Bingo | Name That Element

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This bingo card has a free space and 34 words: Li, Valence Ar, S, Mg, Valence Na, Sc, Valence Al, Valence Rb, Valence S, Be, Valence Cl, Ti, Valence Ga, Na, Valence Cs, C, P, Valence Sr, Cl, Si, F, B, O, Al, N, Ne, Valence Si, Valence Mg, Br, Fe, K, As, Ni and Valence As.

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Classroom Resources | National Center for Science Education

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Classtools.net

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Russel Tarr, International School of Toulouse

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ClassTools.net: Create your own interactive learning resources

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Dozens of templates, quiz generators and learning tools for use in the classroom

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From Wikibooks, open books for an open world

Jump to navigation Jump to search

This page is intended to supply a list of some useful symbols separated by topic so they can be found quickly without the need to search in the Unicode reference tables.

Special Typography Symbols

⏎

23CE carriage return symbol

⌫

232B erase to the left (backspace)

⎵

00A0 non-breaking space - invisible forced space.

-

00AD soft hyphen - is shown where it is inserted in a word if the word is too long for the line and breaks just after the soft hyphen. Otherwise the hyphen is invisible. In several wordprocessors soft hyphen can be entered by holding the control key and at the same time pressing the hyphen key, and is shown as a hyphen with gray background.

​

200B zero-width space - provides a non-printing word separator, an invisible line break opportunity

‌

200C zero-width non-joiner - non-printing character to separate two characters that would otherwise produce a ligature

√ 221A radic, Sqrt, radical, square root

∛ 221B cube root

∜ 221C fourth root

± 00B1 plus or minus

∓ 2213 minus or plus

′ 2032 prime, derivative

″ 2033 Prime, double prime

‴ 2034 tprime, triple prime

∏ 220F N-ary product

∑ 2211 N-ary summation

− 2212 minus

× 00D7 multiplication sign

⋅ 22C5 sdot

∕ 2215 division slash

÷ 00f7 division sign

Calculus, Vector Calculus, Differential Equations

∞ 221E infinity

∂ 2202 partial differential

∫ 222B integral

∬ 222C double integral

∭ 222D triple integral

⨌ 2A0C quadruple integral

∮ 222E contour integral

∯ 222F surface integral

∰ 2230 volume integral

∱ 2231 clockwise integral

∲ 2232 clockwise contour integral

∳ 2233 anticlockwise contour integral

∇ 2207 nabla, Del, backward difference, gradient

∠ 2220 ang, angle

∡ 2221 angmsd, measured angle

∢ 2222 spherical angle

⟂ 27C2 perpendicular to

∟ 221F right angle

¬ 00AC Logical NOT

∧ 2227 Logical AND

∨ 2228 Logical OR

∎ 220E End of proof

∴ 2234 THEREFORE , there4, therefore, Therefore

∵ 2235 BECAUSE , becaus, because, Because

∀ 2200 FOR ALL , forall, for all, ForAll

∃ 2203 THERE EXISTS , exists, exist, Exists

∄ 2204 THERE DOES NOT EXIST , nexist, nexists, NotExists

⋮ 22EE vellip, vertical ellipsis

⋯ 22EF hellip, horizontal ellipsis

⋰ 22F0 utdot, rising dots, up right diagonal ellipsis

⋱ 22F1 dtdot, falling dots, down right diagonal ellipsis

⟨ 27E8, left angle bracket

⟩ 27E9, right angle bracket

° 00B0 degree

ħ 0127 reduced Planck constant

ƛ 019B reduced wavelength

Ψ 03A8 Greek capital letter psi

λ 03BB Greek small letter lambda

ν 03BD Greek small letter nu

ψ 03C8 Greek small letter psi

ω 03C9 Greek small letter omega

⌭ 232D cylindricity (drafting)

Ω 03A9 omega, ohm

℄ 2104 Centerline symbol

﹊ FE4A overline dashes

﹎ FE4E underline dashes

‰ 2030 Per mille

‱ 2031 Basis point, per ten thousand, permyriad

💰 1F4B0 money bag

💱 1F4B1 currency exchange

💳 1F4B3 credit card

📈 1F4C8 chart with upward trend

📉 1F4C9 chart with downward trend

Sports, games

␀ 2400 symbol for null

␆ 2406 symbol for acknowledge

␈ 2408 symbol for backspace

␉ 2409 symbol for horizontal tabulation

␊ 240A symbol for line feed

␍ 240D symbol for carriage return

△ 25B3 equilateral triangle

⊿ 22BF right triangle

⬜ 2B1C square

♢ 2662 lozenge, rhombus, diamond

▭ 25AD rectangle

⬠ 2B20 pentagon

⬡ 2B21 hexagon

○ 25CB circle

⬭ 2B2D ellipse

👍 1F44D Thumbs Up

👎 1F44E Thumbs Down

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Unicode/List of useful symbols - Wikibooks, open books for an open world

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From Wikibooks, open books for an open world Jump to navigation Jump to search This page is intended to supply a list of some useful symbols separated by topic so they can be found quickly without the need to search in the Unicode reference tables.

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What makes a cloud form? What are the different types of clouds? Explore these questions and test your cloud knowledge.

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Waves appear in many different forms. Seismic waves shake the ground during earthquakes. Light waves travel across the universe, allowing us to see distant stars. And every sound we hear is a wave. So what do all these different waves have in common?

A wave is a disturbance that moves energy from one place to another. Only energy - not matter - is transferred as a wave moves.

The substance that a wave moves through is called the medium. That medium moves back and forth repeatedly, returning to its original position. But the wave travels along the medium. It does not stay in one place.

Imagine holding one end of a piece of rope. If you shake it up and down, you create a wave, with the rope as your medium. When your hand moves up, you create a high point, or crest. As your hand moves down, you create a low point, or trough (TRAWF). The piece of rope touching your hand doesn't move away from your hand. But the crests and troughs do move away from your hand as the wave travels along the rope.

J. Look

The same thing happens in other waves. If you jump in a puddle, your foot pushes on the water in one spot. This starts a small wave. The water that your foot hits moves outward, pushing on the water nearby. This movement creates empty space near your foot, pulling water back inwards. The water oscillates, moving back and forth, creating crests and troughs. The wave then ripples across the puddle. The water that splashes at the edge is a different bit of water than where your foot made contact. The energy from your jump moved across the puddle, but the matter (the molecules of water) only rocked back and forth.

Light, or electromagnetic radiation, also can be described as a wave. The energy of light travels through a medium called an electromagnetic field. This field exists everywhere in the universe. It oscillates when energy disturbs it, just like the rope moves up and down as someone shakes it. Unlike a wave in water or a sound wave in air, light waves don't need a physical substance to travel through. They can cross empty space because their medium does not involve physical matter.

Scientists use several properties to measure and describe all these types of waves. Wavelength is the distance from one point on a wave to an identical point on the next, such as from crest to crest or from trough to trough. Waves can come in a wide range of lengths. The wavelength for an ocean wave might be around 120 meters (394 feet). But a typical microwave oven generates waves just 0.12 meter (5 inches) long. Visible light and some other types of electromagnetic radiation have far tinier wavelengths.

Frequency describes how many waves pass one point during one second. The units for frequency are hertz. Traveling through the air, a music note with a frequency of 261.6 hertz (middle C) pushes air molecules back and forth 261.6 times every second.

Frequency and wavelength are related to the amount of energy a wave has. For example, when making waves on a rope, it takes more energy to make a higher frequency wave. Moving your hand up and down 10 times per second (10 hertz) requires more energy than moving your hand only once per second (1 hertz). And those 10 hertz waves on the rope have a shorter wavelength than ones at 1 hertz.

Many researchers rely on the properties and behavior of waves for their work. That includes astronomers, geologists and sound engineers. For example, scientists can use tools that capture reflected sound, light or radio waves to map places or objects.

ttsz/iStock/Getty Images Plus

Power Words
More About Power Words

astronomer: A scientist who works in the field of research that deals with celestial objects, space and the physical universe.

behavior: The way something, often a person or other organism, acts towards others, or conducts itself.

crest: The highest part of a hill, a mountain or a swell of water. (in physics) The top, or highest point, in a wave.

earthquake: A sudden and sometimes violent shaking of the ground, sometimes causing great destruction, as a result of movements within Earth's crust or of volcanic action.

electromagnetic radiation: Energy that travels as a wave, including forms of light. Electromagnetic radiation is typically classified by its wavelength. The spectrum of electromagnetic radiation ranges from radio waves to gamma rays. It also includes microwaves and visible light.

engineer: A person who uses science to solve problems. As a verb, to engineer means to design a device, material or process that will solve some problem or unmet need.

frequency: The number of times some periodic phenomenon occurs within a specified time interval. (In physics) The number of wavelengths that occurs over a particular interval of time.

gamma rays: High-energy radiation often generated by processes in and around exploding stars. Gamma rays are the most energetic form of light.

hertz: The frequency with which something (such as a wavelength) occurs, measured in the number of times the cycle repeats during each second of time.

matter: Something that occupies space and has mass. Anything on Earth with matter will have a property described as "weight."

oscillate: To swing back and forth with a steady, uninterrupted rhythm.

radiation: (in physics) One of the three major ways that energy is transferred. (The other two are conduction and convection.) In radiation, electromagnetic waves carry energy from one place to another. Unlike conduction and convection, which need material to help transfer the energy, radiation can transfer energy across empty space.

radio waves: Waves in a part of the electromagnetic spectrum. They are a type that people now use for long-distance communication. Longer than the waves of visible light, radio waves are used to transmit radio and television signals. They also are used in radar.

range: The full extent or distribution of something. For instance, a plant or animal's range is the area over which it naturally exists.

seismic wave: A wave traveling through the ground produced by an earthquake or some other means.

sound wave: A wave that transmits sound. Sound waves have alternating swaths of high and low pressure.

trough: (in physics) the bottom or low point in a wave.

universe: The entire cosmos: All things that exist throughout space and time. It has been expanding since its formation during an event known as the Big Bang, some 13.8 billion years ago (give or take a few hundred million years).

wave: A disturbance or variation that travels through space and matter in a regular, oscillating fashion.

wavelength: The distance between one peak and the next in a series of waves, or the distance between one trough and the next. It's also one of the "yardsticks" used to measure radiation. Visible light - which, like all electromagnetic radiation, travels in waves - includes wavelengths between about 380 nanometers (violet) and about 740 nanometers (red). Radiation with wavelengths shorter than visible light includes gamma rays, X-rays and ultraviolet light. Longer-wavelength radiation includes infrared light, microwaves and radio waves.

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Explainer: Understanding waves and wavelengths

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Waves appear in many different forms. Seismic waves shake the ground during earthquakes. Light waves travel across the universe, allowing us to see distant stars. And every sound we hear is a wave. So what do all these different waves have in common? A wave is a disturbance that moves energy from one place to another.

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All of this can be an overwhelming transition without a little guidance. Below is:
1. A summary of the different units and their general subjects.
2. Each segment has a link to the unit's specific components.

You can also access the link of the same document on the NGSS site by using the link to the San Diego County Department of Education below.

High School Chemistry in Earth Systems Course Storyline

In this brief introductory unit, students investigate the amount of stored chemical potential energy in food. They make observations of material properties at the bulk scale that they will later explain in the atomic scale. The themes of combustion and CO2 tie together several of the Instructional Segments.

Summary courtesy of San Diego County Department of Education.

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Chemistry in the Earth System - CSUN Guide to CA Science Standards

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All of this can be an overwhelming transition without a little guidance. Below is:1. A summary of the different units and their general subjects.2. Each segment has a link to the unit's specific components. You can also access the link of the same document on the NGSS site by using the link to the San Diego County Department of Education below.

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Create your own bingo card from scratch

Instructions: Enter your bingo card title, choose a size, and type your words into the squares.

You can drag-and-drop images into the squares and customize the color scheme.

To generate your bingo cards, cilck the "Generate" button.

Afterwards, you can print your bingo cards, or play a virtual bingo game.

Features

New! For question/answer-style bingo, flip over the square to enter a question/clue (which will appear on the call list)

Drag and drop images from your computer to liven up your card

Print 10 bingo cards or 10,000 with 1, 2 or 4 bingo cards per page

Play virtual bingo from a computer, tablet or smartphone

Use the automatically generated random call list to conduct your game

Decide if you want to fix your words/images to a single column (like in traditional bingo), or shuffle them across the entire card.

Customize the size of your card with 5x5, 4x4 and 3x3 grids

Add as many words/images as you want

Choose whether you want a free space or not

Calculate the probability of someone winning your bingo game after a certain number of calls

Drag-n-drop an image from your computer into a square

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#1 Free Bingo Card Generator - Play Online or Print Cards

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Create your own bingo cards with words and images, or choose from hundreds of existing cards. Print them or play online. It's easy.

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The Royal Society of Chemistry's interactive periodic table features history, alchemy, podcasts, videos, and data trends across the periodic table. Click the tabs at the top to explore each section. Use the buttons above to change your view of the periodic table and view Murray Robertson's stunning Visual Elements artwork. Click each element to read detailed information.

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Periodic Table - Royal Society of Chemistry

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Interactive periodic table with element scarcity (SRI), discovery dates, melting and boiling points, group, block and period information.

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Using the Concept Builder

The Which One Doesn't Belong - Chemical vs. Physical Properties Concept Builder is shown in the iFrame below. There is a small hot spot in the top-left corner. Clicking/tapping the hot spot opens the Concept Builder in full-screen mode. Use the Escape key on a keyboard (or comparable method) to exit from full-screen mode.

There is a second hot-spot in the lower-right corner of the iFrame. Dragging this hot-spot allows you to change the size of iFrame to whatever dimensions you prefer.

Using the Concept Builder

This Concept Builder will open in a separate browser window on your device. Click the Launch Tool button to open the Concept Builder. Close the window to return to this page.

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what is the difference between chemical and physical changes

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Chemical vs. Physical Properties Concept Builder

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This Chemical vs. Physical Properties Concept Builder engages students in a game-like atmosphere as they use their understanding of the distinction between chemical and physical properties in order to determine which property is not like the others. There are three levels of difficulty and built-in score-keeping as students attempt to earn Stars and complete levels.

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Using the Concept Builder

The Balancing Chemical Equations Concept Builder is shown in the iFrame below. There is a small hot spot in the top-left corner. Clicking/tapping the hot spot opens the Concept Builder in full-screen mode. Use the Escape key on a keyboard (or comparable method) to exit from full-screen mode.

There is a second hot-spot in the lower-right corner of the iFrame. Dragging this hot-spot allows you to change the size of iFrame to whatever dimensions you prefer.

Using the Concept Builder

This Concept Builder will open in a separate browser window on your device. Click the Launch Tool button to open the Concept Builder. Close the window to return to this page.

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Balancing Chemical Equations Concept Builder

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Each interactive concept-builder presents learners with carefully crafted questions that target various aspects of a discrete concept. There are typically multiple levels of difficulty and an effort to track learner progress at each level. Question-specific help is provided for the struggling learner; such help consists of short explanations of how to approach the situation.

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Using the Concept Builder

The Which One Doesn't Belong - Acid-Base Properties Concept Builder is shown in the iFrame below. There is a small hot spot in the top-left corner. Clicking/tapping the hot spot opens the Concept Builder in full-screen mode. Use the Escape key on a keyboard (or comparable method) to exit from full-screen mode.

There is a second hot-spot in the lower-right corner of the iFrame. Dragging this hot-spot allows you to change the size of iFrame to whatever dimensions you prefer.

Using the Concept Builder

This Concept Builder will open in a separate browser window on your device. Click the Launch Tool button to open the Concept Builder. Close the window to return to this page.

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This Acid-Base Properties Concept Builder engages students in a game-like atmosphere as they use their understanding of the distinction between acids and bases in order to determine which property is not like the others. There are three levels of difficulty and built-in score-keeping as students attempt to earn Stars and complete levels.

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Classroom Activities | Center for Science Education

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The UCAR Center for Science Education develops state-of-the-art educational experiences that connect NCAR|UCAR science including weather, climate, air quality, and the Sun-Earth connection, to diverse learners, creating pathways towards a scientifically literate society.

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ScienceCasts: Strange Flames on the International Space Station

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Visible Spectra of the Elements Why care about spectra? Don't spectra all look the same? How can you tell them apart? If the emission lines of the chemical elements were observed through a diffraction grating, they would look something like this (dynamic image - may take a moment to load): Printer-friendly version.

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Key Idea 2
Radioactive and Stable Isotopes

Concept Question: What is the difference between a radioactive isotope and a stable isotope?

There are two types of isotopes: stable and radioactive. Let's look at gold for an example. Gold has 41 known isotopes, ranging from gold-170 to gold-210. Only one of these, gold-197, is stable, the rest are radioactive.

A stable isotope has no experimentally detected nuclear decays. A decay event happens when there is a spontaneous transformation within the nucleus of an atom, changing one isotope to another isotope, or even to another element. Isotopes which undergo these decays are referred to as radioactive, or radioisotopes.

One of the ways we can measure radioactivity is through half-lives. A radioactive half-life is defined as the amount of time it takes for half of a sample of a radioactive isotope to undergo a nuclear decay event. This means that if you have a sample of a radioactive substance with a half-life of 1 day, only half of your sample will be of the original substance after 1 day. The rest of it may become different isotopes of the same element, or atoms a different element.

IUPAC sorts elements into one of three categories based on their half-lives: less than 1 hour, between 1 hour and 1 year, and greater than 1 year. Open the IUPAC Periodic Table of the Elements and Isotopes Learning Tool and click on gold. Select the 'more information' link and read through the document. What kind of technologies can radioactive gold isotopes be used for?

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Key Idea 2 Radioactive and Stable Isotopes Concept Question: What is the difference between a radioactive isotope and a stable isotope? There are two types of isotopes: stable and radioactive. Let's look at gold for an example. Gold has 41 known isotopes, ranging from gold-170 to gold-210.

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Resources For Lesson Plan For Science | PBS LearningMedia

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Discover free resources designed for your lesson plan for science. Explore natural phenomena and scientific practices with videos, games, and activities for all grades.

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Use this easy program to create online jeopardy templates. No more PowerPoint!

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NASA.gov brings you the latest images, videos and news from America’s space agency. Get the latest updates on NASA missions, watch NASA TV live, and learn about our quest to reveal the unknown and benefit all humankind.

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Using the Concept Builder

The Name That Element Concept Builder is shown in the iFrame below. There is a small hot spot in the top-left corner. Clicking/tapping the hot spot opens the Concept Builder in full-screen mode. Use the Escape key on a keyboard (or comparable method) to exit from full-screen mode.

There is a second hot-spot in the lower-right corner of the iFrame. Dragging this hot-spot allows you to change the size of iFrame to whatever dimensions you prefer.

Using the Concept Builder

This Concept Builder will open in a separate browser window on your device. Click the Launch Tool button to open the Concept Builder. Close the window to return to this page.

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Each interactive concept-builder presents learners with carefully crafted questions that target various aspects of a discrete concept. This Concept Builder focuses student attention on the organization of the periodic table and the terminology that is associated with that organization. There are three difficulty levels and an effort to track learner progress at each level.

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Using the Concept Builder

The Classification of Matter Concept Builder is shown in the iFrame below. There is a small hot spot in the top-left corner. Clicking/tapping the hot spot opens the Concept Builder in full-screen mode. Use the Escape key on a keyboard (or comparable method) to exit from full-screen mode.

There is a second hot-spot in the lower-right corner of the iFrame. Dragging this hot-spot allows you to change the size of iFrame to whatever dimensions you prefer.

Using the Concept Builder

This Concept Builder will open in a separate browser window on your device. Click the Launch Tool button to open the Concept Builder. Close the window to return to this page.

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Classifications of Matter Concept Builder

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The Classification of Matter Concept Builder is shown in the iFrame below. There is a small hot spot in the top-left corner. Clicking/tapping the hot spot opens the Concept Builder in full-screen mode. Use the Escape key on a keyboard (or comparable method) to exit from full-screen mode.

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Using the Concept Builder

The Chemical Reaction Types Concept Builder is shown in the iFrame below. There is a small hot spot in the top-left corner. Clicking/tapping the hot spot opens the Concept Builder in full-screen mode. Use the Escape key on a keyboard (or comparable method) to exit from full-screen mode.

There is a second hot-spot in the lower-right corner of the iFrame. Dragging this hot-spot allows you to change the size of iFrame to whatever dimensions you prefer.

Using the Concept Builder

This Concept Builder will open in a separate browser window on your device. Click the Launch Tool button to open the Concept Builder. Close the window to return to this page.

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Each interactive concept-builder presents learners with carefully crafted questions that target various aspects of a discrete concept. There are typically multiple levels of difficulty and an effort to track learner progress at each level. Question-specific help is provided for the struggling learner; such help consists of short explanations of how to approach the situation.

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How Science Is Fixing Recycling's Grossest Problem

- Recycling plastic is complicated.

0:00

6:44

0:00 / 6:44•Watch full video

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How Science Is Fixing Recycling's Grossest Problem

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Freepik | Graphic Resources for everyone

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Millions of Free Graphic Resources. ✓ Vectors ✓ Stock Photos ✓ PSD ✓ Icons ✓ All that you need for your Creative Projects

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Using the Concept Builder

The Bronsted-Lowry Acid-Base Model Concept Builder is shown in the iFrame below. There is a small hot spot in the top-left corner. Clicking/tapping the hot spot opens the Concept Builder in full-screen mode. Use the Escape key on a keyboard (or comparable method) to exit from full-screen mode.

There is a second hot-spot in the lower-right corner of the iFrame. Dragging this hot-spot allows you to change the size of iFrame to whatever dimensions you prefer.

Using the Concept Builder

This Concept Builder will open in a separate browser window on your device. Click the Launch Tool button to open the Concept Builder. Close the window to return to this page.

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Bronsted-Lowry Acid-Base Model - Concept Builder

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Each interactive concept-builder presents learners with carefully crafted questions that target various aspects of a discrete concept. There are typically multiple levels of difficulty and an effort to track learner progress at each level. Question-specific help is provided for the struggling learne…

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Using the Concept Builder

The Molar Mass Concept Builder is shown in the iFrame below. There is a small hot spot in the top-left corner. Clicking/tapping the hot spot opens the Concept Builder in full-screen mode. Use the Escape key on a keyboard (or comparable method) to exit from full-screen mode.

There is a second hot-spot in the lower-right corner of the iFrame. Dragging this hot-spot allows you to change the size of iFrame to whatever dimensions you prefer.

Using the Concept Builder

This Concept Builder will open in a separate browser window on your device. Click the Launch Tool button to open the Concept Builder. Close the window to return to this page.

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The Molar Mass Concept Builder is shown in the iFrame below. There is a small hot spot in the top-left corner. Clicking/tapping the hot spot opens the Concept Builder in full-screen mode. Use the Escape key on a keyboard (or comparable method) to exit from full-screen mode.

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Using the Concept Builder

The Significant Digits and Measurement Concept Builder is shown in the iFrame below. There is a small hot spot in the top-left corner. Clicking/tapping the hot spot opens the Concept Builder in full-screen mode. Use the Escape key on a keyboard (or comparable method) to exit from full-screen mode.

There is a second hot-spot in the lower-right corner of the iFrame. Dragging this hot-spot allows you to change the size of iFrame to whatever dimensions you prefer.

Using the Concept Builder

This Concept Builder will open in a separate browser window on your device. Click the Launch Tool button to open the Concept Builder. Close the window to return to this page.

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Significant Digits and Measurement Concept Builder

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This interactive concept-builder targets student understanding of the measurement process and the importance of expressing measured values to the proper number of significant digits. The need to use the provided markings on a measuring tool along with an estimated digit is the focus of the second activity.

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NASA Models the Complex Chemistry of Earth's Atmosphere

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Depicted above are two videos of the same ice cubes melting. The ice cubes were placed in a crystallization dish, which was then placed on a hot plate. The left video is a visible light video of the event. This video depicts how your eye would capture the event. The right video is an infrared video, which depicts the infrared radiation emitted or reflected from the objects. Since the infrared radiation emitted by an object corresponds to its temperature, the infrared video allows us to quantify the temperature of the ice as it melts, and later boils. Press the Play button to watch the videos, and once they have completed, press the Show Heating Curve button to rewatch the video with a simulated heating curve of the melting ice.

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IR Imaging of Phase Changes Learning Tool

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Depicted above are two videos of the same ice cubes melting. The ice cubes were placed in a crystallization dish, which was then placed on a hot plate. The left video is a visible light video of the event. This video depicts how your eye would capture the event.

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Depicted above are two videos of the same ice cubes melting. The ice cubes were placed in a crystallization dish, which was then placed on a hot plate. The left video is a visible light video of the event. This video depicts how your eye would capture the event. The right video is an infrared video, which depicts the infrared radiation emitted or reflected from the objects. Since the infrared radiation emitted by an object corresponds to its temperature, the infrared video allows us to quantify the temperature of the ice as it melts, and later boils. Press the Play button to watch the videos, and once they have completed, press the Show Heating Curve button to rewatch the video with a simulated heating curve of the melting ice.

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IR Imaging of Phase Changes Learning Tool

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Depicted above are two videos of the same ice cubes melting. The ice cubes were placed in a crystallization dish, which was then placed on a hot plate. The left video is a visible light video of the event. This video depicts how your eye would capture the event.

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I'm not sure where I first saw this poster, but knew right away it would look great in a chemistry classroom. It captures each element's unique spectrum, which demonstrates how these spectra can be used as a fingerprints to identify elements. Field Tested Systems created this poster to go along with its many products that allow students - and their teachers - to explore classroom gas-tube spectroscopy and astronomical spectroscopy. For example, one of the products is a desktop spectrometer that has a built-in video camera that can plug into your computer. Your students can make real-time videos of their gas tubes. My favourite product is a webcam and telescope to capture the spectra of the stars. Students can identify the elements of the stars from their own backyard. This would be a fantastic tool for your chemistry classroom.

The classroom-sized (24″ x 36″) periodic table of spectra poster is available online at www.fieldtestedsystems.com.

The laminated poster is US $29.95 (plus shipping).

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Periodic Table of emission spectra | Chem13 News Magazine

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I'm not sure where I first saw this poster, but knew right away it would look great in a chemistry classroom. It captures each element's unique spectrum, which demonstrates how these spectra can be used as a fingerprints to identify elements.

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Since there's no "established in" plaque stuck in a cliff somewhere, geologists deduced the age of the Earth thanks to a handful of radioactive elements. With radiometric dating, scientists can put an age on really old rocks - and even good old Mother Earth. For the 30th anniversary of National Chemistry Week, this edition of Reactions describes how scientists date rocks.

Aired: 09/10/18

Rating: NR

From:

Problems Playing Video? Report a Problem |

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Reactions | How Do We Know How Old the Earth Is? | Season 1

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Since there's no "established in" plaque stuck in a cliff somewhere, geologists deduced the age of the Earth thanks to a handful of radioactive elements. With radiometric dating, scientists can put an age on really old rocks - and even good old Mother Earth.

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Stoichiometry - Math Relationships Concept Builder

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This interactive concept-builder presents learners with a chemical equation and a table listing amounts of reactants and products. Learners must complete the table using an understanding of coefficients and molar mass.There are three levels of difficulty and an effort to track learner progress at ea…

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Explore Chemistry - American Chemical Society

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American Chemical Society: Chemistry for Life.

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40+ FREE digital escape rooms (plus a step by step guide for creating your own)

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Digital escape rooms bring the excitement of hunting for clues and the joy of solving puzzles right to your student’s devices. Here are over 40 digital

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Reactions | Catalytic Converter Stolen? Here's Why. | Season 4

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Catalytic converter theft is on the rise, and that's partly because of their chemistry.

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The following activities target a middle and high school population although some content is approachable by more advanced elementary school students. The page is also an excellent review for higher level students. All exercises make use of javascript's which provides for a more interactive environment.
Everything on Earth can be explained in terms of 4 states (phases) of matter-- solid, liquid, gas, and plasma.
What are the properties of a solid?

A substance in a solid phase is relatively rigid, has a definite volume and shape.

The atoms or molecules that comprise a solid are packed close together and are not compressible.

Because all solids have some thermal energy, its atoms do vibrate. However, this movement is very small and very rapid, and cannot be observed under ordinary conditions.

What are the different types of solids?
There are four types of crystalline solids --

Ionic solids-- These substances have a definite melting point and contain ionic bonds. An example would be sodium chloride (NaCl). View the 3-D structure of a salt crystal.

"
Covalent solids -- These substance appear as a single giant molecule made up of an almost endless number of covalent bonds. An example would be graphite. View the 3-D structure of graphite).

Molecular solids are represented as repeating units made up of molecules. An example would be ice. View the 3-D structure of ice.

Metallic solids are repeating units made up of metal atoms. The valence electrons in metals are able to jump from atom to atom.

Amorphous solids

Amorphous solids do not have a definite melting point or regular repeating units. An amorphous solid is a solid in which there is no long-range order of the positions of the atoms unlike those in crystalline solids. An example of an amorphous solid is window glass. In addition many polymers such as polystyrene are amorphous.Amorphous solids can exist in two distinct states, the 'rubbery' state and the 'glassy' state. The temperature at which they transition between the glassy and rubbery states is called their glass transition temperature or Tg.

Interesting Note on Solids: While no mass at all is an impossibility, aerogels seem to come pretty close. Aerogels are the lightest solids and have a density of 1.9 mg per cm3 or 1.9 kg/m3 (526.3 times lighter than water). Sometimes called frozen smoke, aerogels are open-cell polymers with pores less than 50 nanometers in diameter.

What are the properties of a Liquid?

Liquids have a definite volume, but are able to change their shape by flowing.

Liquids are similar to solids in that the particles touch. However the particles are able to move around.

Since particles are able to touch, the densities of liquid will be close to that of a solid.

Since the liquid molecules can move, they will take the shape of their container.
What are the specific properties of liquids?
Viscosity --The resistance of a liquid to flow is called its viscosity

Surface Tension -- The result of attraction between molecules of a liquid which causes the surface of the liquid to act as a thin elastic film under tension. Surface tension causes water to form spherical drops.

Vapor Pressure -- The pressure that a solid or liquid exerts when it is in equilibrium with its vapor at a given temperature.

Boiling Point -- when vapor pressure = atmospheric pressure.

What are the properties of a Gas?

Gases have no definite volume or shape. If unconstrained gases will spread out indefinitely. If confined they will take the shape of their container. This is because gas particle have enough energy to overcome attractive forces. Each of the particles are well separated resulting in a very low density.

What is the fourth state of matter?

The fourth state of matter is plasma. Plasma is an ionized gas, a gas into which sufficient energy is provided to free electrons from atoms or molecules and to allow both species, ions and electrons, to coexist. In effect a plasma is a cloud of protons, neutrons and electrons where all the electrons have come loose from their respective molecules and atoms, giving the plasma the ability to act as a whole rather than as a bunch of atoms. Plasmas are the most common state of matter in the universe comprising more than 99% of our visible universe and most of that not visible. Plasma occurs naturally and makes up the stuff of our sun, the core of stars and occurs in quasars, x-ray beam emitting pulsars, and supernovas. On earth, plasma is naturally occurring in flames, lightning and the auroras. Most space plasmas have a very low density, for example the Solar Wind which averages only 10 particles per cubic-cm. Inter-particle collisions are unlikely - hence these plasmas are termed collisionless.

And now a fifth state -- Bose Einstein?

The collapse of the atoms into a single quantum state is known as Bose condensation or Bose-Einstein condensation is now considered a 5th state of matter.

Recently, scientists have discovered the Bose-Einstein condensate, which can be thought of as the opposite of a plasma. It occurs at ultra-low temperature, close to the point that the atoms are not moving at all. A Bose-Einstein condensate is a gaseous superfluid phase formed by atoms cooled to temperatures very near to absolute zero. The first such condensate was produced by Eric Cornell and Carl Wieman in 1995 at the University of Colorado at Boulder, using a gas of rubidium atoms cooled to 170 nanokelvins (nK). --Under such conditions, a large fraction of the atoms collapse into the lowest quantum state, producing a superfluid. This phenomenon was predicted in the 1920s by Satyendra Nath Bose and Albert Einstein, based on Bose's work on the statistical mechanics of photons, which was then formalized and generalized by Einstein.

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The following activities target a middle and high school population although some content is approachable by more advanced elementary school students. The page is also an excellent review for higher level students. All exercises make use of javascript's which provides for a more interactive environment.

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Reactions | Why is the Statue of Liberty Green? | Season 4 | PBS

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Her color change is thanks to about 30 years' worth of chemistry in New York City's air.

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VSEPR is a simple theory used to predict the shape of a molecule. It assumes that groups of electrons, either non-bonding (lone pairs) or groups of bonding electrons (this would include ALL bonding electrons to an atom, i.e. single, double, or triple bonds) will arrange themselves around the central atom to minimize the electron-electron repulsions. This results in five basic VSEPRelectronic geometries; linear, trigonal planar, tetrahedral, trigonal bipyramidal, and octahedral, based on two, three, four, five and six groups of electrons respectively.

There maybe more than one molecular geometry associated with each electronic geometry.

The electronic geometry refers to ALL electrons, both bonding and non-bonding, that surround the central atom.

The molecular geometry refers to the relative locations of only the atoms.

VSEPR notation is a common shorthand for the electronic structure. In this notation A represents the central atom, X the atom (or group of atoms) bonded to the central atom, andE lone pairs of electrons.

Placement of electrons?

The starting point is a valid Lewis Structure.

If there are lone pair(s) of electrons, arrange them around the central atom to maximize their distance to other lone pair electrons first, and then to other bonding groups of electrons (i.e. see the AX₄E, AX₃E₂ and AX₄E₂ geometries below, this is because the lone pair electrons are closer to the nucleus and thus repel bonding electrons stronger than other bonding electron pairs repel each other).

If there are multiple bonds present arrange them around the central atom to maximize their distance to other pairs of electrons. Since there are four electrons in a double bond they will repel another pair of electrons stronger than the two electrons in a single bond. Triple bonds with six electrons will repel other bonding electrons even stronger. See the figure below:

The oxygen is doubly bonded while the F atoms are singly bonded, the higher electron density in the double bond means it requires a larger repulsion between it and any other bonds. The four equatorial bonding-pair bonding-pair contacts of 2 x 120° and 2 x 90° (left image) is more favourable than the than the three bonding-pair bonding-pair contacts of 3 x 90° (right image).

The images are displayed using Jmol. Check this link if you are not familiar with Jmol.

Note: the atom colors are:

B C N O F S Br I P Te Xe H

Electronic Geometry

Molecular Geometry 3-D Jmol images (requires Red-Cyan (or Red-Blue) anaglyph 3D stereo glasses)

Linear

Trigonal Planar

Trigonal Planar (AX₃)

BH₃

Bent (AX₂E)

SO₂

Tetrahedral

Tetrahedral (AX₄)

CH₄

Trigonal Pyramidal (AX₃E)

NH₃

Bent (AX₂E₂)

H₂O

Trigonal Bipyramidal

Trigonal Bipyramidal (AX₅)

PF₅

See Saw (AX₄E)
TeF₄

T-Shaped (AX₃E₂)
BrF₃

Linear (AX₂E₃)

XeF₂

Octahedral

Octahedral (AX₆)

SF₆

Square Pyramidal (AX₅E)
IF₅

Square Planar (AX₄E₂)

XeF₄

© R. Spinney 2003 - 2015

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VSEPR is a simple theory used to predict the shape of a molecule. It assumes that groups of electrons, either non-bonding (lone pairs) or groups of bonding electrons (this would include ALL bonding electrons to an atom, i.e. single, double, or triple bonds) will arrange themselves around the central atom to minimize the electron-electron repulsions.

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Hands-On Math Goes Digital In and Beyond the Classroom!

Explore Our Collection of FREE Virtual Manipulatives

From Number Lines to Base Ten, Pattern Blocks to Place Value, Disks our collection of free Virtual Manipulatives gives educators and families access to visual and hands-on digital resources that lead to understanding. Students can use these resources in class and at home to practice math concepts, reinforce their growing math understanding, technology they love in the process.

Free Resources & Instructions for Teachers and Families

We've developed these resources for easy access and easy use:

How-To Videos

There's a short video for each of the Virtual Manipulatives in our collection so teachers can use these digital materials easily and confidently with students.
Watch Now

Activities

Activities from the Didax books that teachers use most for easy download. Engaging challenges address core math operations, concepts and skills, from early numeracy all the way to introductory geometry and algebra.
Access Now

FAQ

Download this document of FAQ's to answer your Virtual Manipulative questions.
Download Now

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Demonstrate key math concepts in your classroom using our new virtual manipulatives!

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The pH Scale (animation) - Annenberg Learner

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The pH scale runs from zero to 14, with zero being the most acidic, 14 the most basic and seven…

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Using the Concept Builder

The Particles .. Moles .. Mass Concept Builder is shown in the iFrame below. There is a small hot spot in the top-left corner. Clicking/tapping the hot spot opens the Concept Builder in full-screen mode. Use the Escape key on a keyboard (or comparable method) to exit from full-screen mode.

There is a second hot-spot in the lower-right corner of the iFrame. Dragging this hot-spot allows you to change the size of iFrame to whatever dimensions you prefer.

Using the Concept Builder

This Concept Builder will open in a separate browser window on your device. Click the Launch Tool button to open the Concept Builder. Close the window to return to this page.

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This interactive Concept Builder includes three scaffolded difficulty levels to insure student understanding of the mathematics associated with mole-particle conversions and mole-gram conversions. The Concept Builder includes immediate feedback to student answers. There are pop-up Help screens with Conversion Factor examples.

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Using the Concept Builder

The Measurement and Numbers Concept Builder is shown in the iFrame below. There is a small hot spot in the top-left corner. Clicking/tapping the hot spot opens the Concept Builder in full-screen mode. Use the Escape key on a keyboard (or comparable method) to exit from full-screen mode.

There is a second hot-spot in the lower-right corner of the iFrame. Dragging this hot-spot allows you to change the size of iFrame to whatever dimensions you prefer.

Using the Concept Builder

This Concept Builder will open in a separate browser window on your device. Click the Launch Tool button to open the Concept Builder. Close the window to return to this page.

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The Measurement and Numbers Concept Builder is shown in the iFrame below. There is a small hot spot in the top-left corner. Clicking/tapping the hot spot opens the Concept Builder in full-screen mode. Use the Escape key on a keyboard (or comparable method) to exit from full-screen mode.

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The Ideal Gas Law is a model that accurately describes how most common gases behave within the temperature and pressure ranges in which we live. It was developed in stages over the 17th, 18th, and 19th centuries, starting with chemist Robert Boyle, who noted the relationship of pressure and volume. Today, the Ideal Gas Law finds expression in the equation PV = nRT, where P is pressure, V is volume, T is temperature, n is the number of particles in the gas, and R is a mathematical constant.

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Gases and the Roles of Pressure, Volume, and Temperature (animation) - Annenberg Learner

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The Ideal Gas Law is a model that accurately describes how most common gases behave within the temperature and pressure ranges in which we live. It was developed in stages over the 17th, 18th, and 19th centuries, starting with chemist Robert Boyle, who noted the relationship of pressure and volume.

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Today's news has been dominated by the terrible explosion in Beirut, Lebanon. The blame for the explosion has been directed at 3,000 tons of ammonium nitrate that was being stored in a warehouse in Beirut's port. What is ammonium nitrate, why can it explode, and what happens when it does? This graphic takes a look.

Ammonium nitrate's major use is as a fertiliser - this accounts for around 78% of its use (by volume) worldwide. It's a source of nitrogen, important for the growth of plants.

It's also used in some explosive mixtures which are used for mining and quarrying. Mixed with fuel oil it's known as ANFO (ammonium nitrate/fuel oil), which accounts for approximately 80% of the 2.7 billion kilograms of explosives used in North America every year. In these explosive mixtures, it acts as an oxidising agent, helping other materials burn.

In its pure form, ammonium nitrate isn't usually explosive - in fact, it's safe to handle. However, if it is contaminated with impurities, the risk of it detonating increases. Heating also poses a danger: ammonium nitrate decomposes at around 230˚C, and can explode when heated to between 260-300˚C if it's confined.

The force of the ammonium nitrate explosion is provided by the rapid generation of gas as it breaks down. The primary reaction when it breaks down produces nitrogen, water vapour and oxygen.

This reaction isn't the only one taking place, however. You might have wonder what caused the plume of smoke seen after the explosion in Beirut to have an orange-red colour. This is due to other reactions generating nitrogen dioxide. It's not the only additional product: ammonia and nitrous oxide are amongst the others.

If you want to learn more about the chemistry behind ammonium nitrate explosions, I've provided some useful links below. If you're looking to help the huge numbers of people affected by the explosion in Beirut, the Lebanese Red Cross is accepting donations, and Impact Lebanon are raising disaster relief funds.

The graphic in this article is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License. See the site's content usage guidelines.
References/further reading

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What is ammonium nitrate and what happens when it explodes?

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Today's news has been dominated by the terrible explosion in Beirut, Lebanon. The blame for the explosion has been directed at 3,000 tons of ammonium nitrate that was being stored in a warehouse in Beirut's port. What is ammonium nitrate, why can it explode, and what happens when it does?

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Daily Do

Why Is Water Sphere-Shaped in Space?

1. NSTA

2. Why Is Water Sphere-Shaped in Space?

Welcome to NSTA's Daily Do

Teachers and families across the country are facing a new reality of providing opportunities for students to do science through distance and home learning. The Daily Do is one of the ways NSTA is supporting teachers and families with this endeavor. Each weekday, NSTA will share a sensemaking task teachers and families can use to engage their students inauthentic, relevant science learning.We encourage families to make time for family science learning (science is a social process!) and are dedicated to helping students and their families find balance between learning science and the day-to-day responsibilities they have to stay healthy and safe.

Interested in learning about other ways NSTA is supporting teachers and families? Visit the NSTA homepage.

What Is Sensemaking?

Sensemaking is actively trying to figure out how the world works (science) or how to design solutions to problems (engineering). Students do science and engineering through the science and engineering practices. Engaging in these practices necessitates that students be part of a learning community to be able to share ideas, evaluate competing ideas, give and receive critique, and reach consensus. Whether this community of learners is made up of classmates or family members, students and adults build and refine science and engineering knowledge together.

Introduction

Did you know humans have been living in space for the last 20 years? NASA is currently celebrating the Year of Recognition, highlighting the anniversary of 20 years of continuous human presence aboard the International Space Station on November 2, 2020.

Fluids-gases and liquids-are everywhere in our lives. The Earth, known as "the water planet," is able to support life in part because of the presence of water. Understanding the basic principles of fluid motion, such as with water, is important for all walks of life. The behavior of water on the International Space Station (ISS) is not only mesmerizing and beautiful to observe (see picture below), but also researchers are using these observations to figure out why fluids behave differently in microgravity than they do on Earth. The near-weightless conditions aboard the ISS allow researchers to observe and control a wide variety of fluids in ways that are not possible on Earth. Understanding how fluids react in these conditions could lead to improved designs for space travel, as well as back on Earth.

In today's task, Why Is Water Sphere-Shaped in Space?, students and their families engage in science and engineering practices to make sense of the phenomenon of liquid water forming a perfect sphere-shape in space. Students see how the science ideas that explain water's sphere-shape in space are applied to the design of the Space Coffee Cup, then brainstorm solutions to other problems astronauts encounter that will help people live in space! While students could complete this task independently, we encourage students to work virtually with peers or in the home with family members.

Part 1: Why Does Water Form a Sphere in Space?

When people think of a liquid, they usually think of water. Students have many experiences with water and how it behaves on Earth. Water is so common and so familiar that it is mundane: Every day we drink it, touch it, wash with it, wet things, dry things, boil it, freeze it, and swim in it. We live in a world where the environmental conditions allow water to exist as a solid, liquid, and gas; where slight changes in temperature and pressure can cause water to alternate among phases (or sometimes be all three at once). The more we examine water, the stranger it gets. But few have had experiences with how it behaves in space!

Tell students, "We are going to watch this video of an interesting phenomenon in space!"

Ask them to make a simple T-chart on blank paper or in their science notebooks. Label one side "Notice" and the other side "Wonder," and ask them to record their observations and questions that arise as they watch the video.

Ask students to share their noticings with two or three other students (small group) and to identify (1) two or three observations everyone in the group had and (2) one observation that only one or two group members noticed. You may choose to create a class list of observations.
Note: Students have probably heard about water surface tension, but may not be able to use that science idea to explain why the water behaves the way it does on the ISS. If students don't bring up surface tension, that's okay.
Ask students to create an initial model to explain why the water squeezed from the pouch formed a sphere that the candy was able to stick to/sit on.

If students are struggling to begin, ask them, "What absolutely needs to be included in your model? In other words, what are the components of the model?" (water molecules, forces, molecular bonds, air, candy) Ask, "How could you show how the components of your model are interacting?" (arrows, lines, labels, text)

Working in pairs or small groups, ask students to compare their models and identify similarities and differences. You might ask student groups to create a consensus model. If you choose to do this, students can do a gallery walk. Ask them to use sticky notes to identify something on other groups' models that they like (maybe they like the way a group represented components interacting, for example) and one thing they have a question about. Allow the groups to add to or change their models after the gallery walk.

Before moving to the next investigation, give students an opportunity to think about related phenomena. These prompts may help elicit students' ideas:

What experiences do you have that might help you think about this phenomenon?

Is this something you've heard about, observed, or experienced before?

What questions does this raise for you?"

Notes for Educators (Teachers and Families)

Here on Earth, we all live in a state of gravity. Not only us, but everything around us, including water, is being pulled toward the center of the planet by gravity. But if you go far enough out in space, for instance, onto the International Space Station, gravity becomes negligible, and the laws of physics act differently than here on Earth. Just how might water act in a place of zero gravity? Actually, on the ISS, there is plenty of gravity. According to NASA scientists, the pull of Earth's gravity on the space station and its occupants is substantial: about 90% of the force at the Earth's surface. But since the space station is continuously falling around our planet, the astronauts and objects on board are in a kind of free-fall, too, and feel nearly weightless. Water on the space station behaves as if in a zero-gravity environment.

Part 2: Let's Explore How Water Behaves!

Tell students they are going to do a NASA investigation in their own home! Students and families will need to gather these household materials to see water behave in ways similar to how it does in space.

Materials

Small disposable cups (Plastic 7-oz. cups work great!)

Glass of water to fill cups and droppers
Explore!
Let students explore without providing any explanation.

1. Place the plastic cup on a paper towel and fill the cup to the very top with water.

2. Add drops of water to the cup using the water dropper to see how high you can get the water above the rim without spilling over. (Record observations on paper using words, pictures, symbols, etc.)

3. Now gently place a grain of rice on the water. (Record observations.)

4. Next, take another grain of rice and throw it (give it a big push from your hand) onto the water surface. (Record observations.)

Set the cup aside and place a penny flat on a paper towel. Use the water dropper to carefully add water to the surface of the penny until it spills over. Try to keep the drops the same size. (Record observations.)
Discuss
Use the following prompts to spark discussion:

1. How many drops did it take to overflow the cup or spill over the sides of the penny?

2. Why do you think you were able to add water drops higher than the top rim of the cup or higher than the surface of the penny without it flowing over at first?

3. Why do you think the first grain of rice stayed on the water surface?

4. Why do you think the second grain of rice acted differently?

Tell students they can use the words surface tension to communicate their observations to other students and scientists. (At this point in the task, ask students to revise their models using evidence from these investigations.)

Notes for Educators

Surface tension is a property of liquids in which molecules of one substance are more attracted to one another than to molecules of another substance. Water is unique in that it has a high surface tension compared to other liquids. We observe this when water beads up on glass. Water molecules are able to form hydrogen bonds due to the polarity of the H₂O molecule. The slightly positive ends of the hydrogen atoms and the slightly negative end of the oxygen atom attract other H₂O molecules, forming a hydrogen bond, and causing water to have high surface tension. At water's surface, its molecules are only attracted to the water molecules below and to the sides of them, as there is only air above these molecules. Therefore, the surface molecules of a body of water are pulled down, creating a much more stable, stronger arrangement.
More force is needed to break the water molecules' bond, which is why the second grain of rice broke through and sank to the bottom of the cup.

STEMonstration: Surface Tension!

Ask students the following questions to help navigate them to the STEMonstration: Surface Tension! video.

1. What would happen if you tried these experiments in microgravity?

2. Would the water behave differently in microgravity? Why or why not?

3. In microgravity, does surface tension exist? Why or why not?

Have students watch this episode of STEMonstrations, which features NASA astronaut Ricky Arnold explaining how water's unique molecular bonding properties create quite the spectacle in microgravity!

Ask students to revise their individual or group models using evidence from the STEMonstrations: Surface Tension! video.

Ask students to find a partner (or groups to find another group) and share what they added to or changed on their model and why. (What evidence from their investigations or the video did they base their changes on?)

Lead the students in a consensus discussion. Consider using the following prompts:

What are some things we think we can say about why water forms a sphere in space? What is our evidence for those ideas (those explanations)?

What ideas are we in consensus about?

Are there still places where we disagree?

You might choose to draw a consensus model, then have all students record the class consensus model on blank paper or in student notebooks. If you are working with middle school students, it is okay if they don't include molecular bonds in their models as long as they represent the fact that water molecules at the surface are more tightly together/have higher attraction to one another/etc.

Notes to Educators

How do we know surface tension in microgravity is no different than on Earth? The chemical bonding mechanisms for water molecules do not change in microgravity. These cohesive bonds are hydrogen bonds and are formed when the slightly positive (hydrogen) end of one water molecule is attracted to the slightly negative (oxygen) end of another water molecule, forming a series of water molecules that "stick" together and help produce water's high surface tension. At the surface, water molecules are only attracted to other water molecules below and to the sides of them, and the inner cohesive forces are pulling these molecules together. Therefore, the surface molecules of a body of water are experiencing a net inward force, creating a much more stable, stronger arrangement. On the International Space Station, surface tension of water is much more obvious than on Earth due to the microgravity environment. What variables are acting on the water? One variable is the amount of gravity acting on the water. Whether water sits in a lake or in a glass, Earth's gravity pulls the liquid downward into the shape of the container it's in. But in space, gravity's effects are different. Objects in orbit are indeed affected by gravity, but they are in free-fall, moving constantly sideways while falling toward Earth. This renders them effectively weightless. Up there, surface tension among the tight-knit group of water molecules forms the smallest possible area: a sphere. On Earth, gravity distorts the shape, but not in space.

Part 3: Engineering a Good Life in Space!

The Engineering Design Process (EDP) comes in many forms. Engineers enter the EDP to create a new technology-or improve an existing one-to meet a need or want. Engineers on the job may start at any step, depending on the needs of a particular project.

Share the The Zero Gravity Coffee Cup video with your students to find out how engineers helped astronauts drink a real cup of coffee in space. Ask students, "As you watch the video, can you identify the steps of the EDP used to design a solution to the problem of how can we drink a cup of liquid coffee in space? What's your evidence?"

Watch this video to learn about more challenges astronauts encounter in space. Does the video spark an idea for a new technology (object, system, or process) that would help make life in space easier and that you could design using the engineering design process?

Part 4: Explore STEM Careers: Astronaut Launch!

Share with students, "Now that you and the researchers figured out why water is sphere-shaped in space, explore what it takes to enter the exciting STEM career as an astronaut!"
STEM Career Awareness is an important part of educating and preparing our students for the future workforce. Students can explore the challenging and rewarding career of a NASA astronaut by watching and discussing these two videos.

How Did Leland Melvin Reach for the Stars?

Learn how Astronaut Leland Melvin, whom you met in the first video (playing with water and candy), went from NFL star to astronaut!

NSTA Collection of Resources for Today's Daily Do

Check Out Previous Daily Dos From NSTA

The NSTA Daily Do is an open educational resource (OER) and can be used by educators and families providing students distance and home science learning. Access the entire collection of NSTA Daily Dos.

Acknowledgments

This Daily Do is adapted from a NASA STEM demonstration or STEMonstrationon Surface Tension. Please check the collection for the link and to explore other STEMonstrations to try!

Thank you, NASA Office of STEM Engagement at Johnson Space Center, for sharing your expertise and resources! stem.nasa.gov

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Daily Do NSTA Why Is Water Sphere-Shaped in Space? Welcome to NSTA's Daily Do Teachers and families across the country are facing a new reality of providing opportunities for students to do science through distance and home learning. The Daily Do is one of the ways NSTA is supporting teachers and families with this endeavor.

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A neat website where you can see the atomic emission spectrum of different elements. NOTE: While each element does have it's own unique emission spectrum, this website does not have the emission spectrum of every element on the periodic table.

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1. In the formation of carbon dioxide from carbon monoxide and oxygen, how many moles of carbon monoxide are needed to react completely with 7.0 moles of oxygen gas?

2. How many moles of carbon dioxide, CO ₂, can be formed by the decomposition of 5 moles of aluminum carbonate, Al ₂(CO ₃) ₂?

3. In the formation of carbon dioxide from carbon monoxide and oxygen, how many liters of carbon monoxide, CO, are needed to react completely with 1/2 mole of oxygen gas at STP?

4. How many moles of oxygen are required to burn 22.4 liters of ethane gas, C ₂H ₆ at standard conditions?

5. How many grams of oxygen are produced by the decomposition of 1 mole of potassium chlorate, KClO ₃?

6. A chemist performs the synthesis of sodium chloride from its elements. The chemist begins with 46 grams of sodium. How many moles of chlorine are needed?

7. How many grams of water can be prepared from 5 moles of hydrogen at standard conditions?

8. Suppose that an excess of propane, C ₃H ₈ burns in 320 g of O ₂. How many moles of H ₂O will be formed?

9. At standard conditions, how many liters of carbon dioxide, CO ₂, will be formed by the combustion of 1/2 mole of propane, C ₃H ₈?

10. Ammonia, NH ₃, is commercially prepared by the Haber process. How many moles of ammonia can be formed from 44.8 liters of nitrogen gas and an excess of hydrogen at standard conditions?

11. How many liters of hydrogen, H ₂, are needed to react with 10 liters of nitrogen gas in the reaction forming ammonia?

12. How many grams of water can be prepared from 8 grams of hydrogen at standard conditions?

13. How many grams of carbon dioxide are produced by the combustion of 22.4 liters of ethane gas, C ₂H ₆ at standard conditions?

14. How many liters of oxygen, at standard conditions, are required to react with 30 grams of glucose, C ₆H ₁₂O ₆?

15. How many grams of calcium must react with of sulfuric acid, H ₂SO ₄, in order to produce 5.6 liters of hydrogen gas?

16. How many grams of calcium will react with 44.8 liters of oxygen gas at standard conditions?

17. A certain amount of glucose, C ₆H ₁₂O ₆ burned in oxygen, and produced 22 grams of carbon dioxide, CO ₂. How many grams of water was produced at the same time?

18. How many liters of oxygen are required to react completely with 22.4 liters of carbon monoxide, CO, at standard conditions?

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Created with Hot Potatoes by Half-Baked Software, registered to Andy Allan.

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1. In the formation of carbon dioxide from carbon monoxide and oxygen, how many moles of carbon monoxide are needed to react completely with 7.0 moles of oxygen gas? 2. How many moles of carbon dioxide, CO 2, can be formed by the decomposition of 5 moles of aluminum carbonate, Al 2(CO 3) 2?

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AACT is a professional community by and for K–12 teachers of chemistry

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Out of Our Elements
Why is water so crucial to us-and to all life on Earth? Out of Our Elements hosts Caitlin Saks and Arlo Pérez Esquivel examine their sweat to understand how the molecular structure of water makes it crucial for life as we know it. They also explore how the same molecular properties that make water essential for life come with a downside, helping to explain why we are facing a global water crisis.

Aired: 07/08/21

Rating: NR

From:

Problems Playing Video? Report a Problem |

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Out of Our Elements | What Does Sweat Have to do with the Global Water Crisis? | Episode 1

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Out of Our Elements Why is water so crucial to us-and to all life on Earth? Out of Our Elements hosts Caitlin Saks and Arlo Pérez Esquivel examine their sweat to understand how the molecular structure of water makes it crucial for life as we know it.

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A printable periodic table is an essential tool for students and chemists. You can place it where you need it while solving problems, mark it up, and print a new one whenever you like. This is a collection of free printable periodic tables in PDF file or PNG image format to save, print, and use. What we've done is list the tables, along with links, so you can get detailed info about each one. The HD periodic tables make great screen savers or reference tables on mobile devices. They are sized to fit on a sheet of paper and you don't need to worry about marking them up because you can always print more for working homework problems or performing lab calculations. The tables re-size cleanly, so you can view or print at any size or aspect ratio, from tiny to poster-sized.

To download a table, click the image for the full-size version to right-click and save. PDF periodic tables and additional color options are available on each table's main page via the link.

Periodic Table Thumbnail

Periodic Table Description

118 Element Color Printable Periodic Table
Do you want all the latest element facts and figures? This printable periodic table cites the atomic mass significant figures in keeping with the most recent IUPAC values. This is the periodic table we recommend you use for calculations and homework. You can right-click the image to download it or grab the PDF file of the periodic table.

2019 Printable Periodic Table
New for 2019! This printable periodic table cites the IUPAC standard atomic mass values. This is an accurate up-to-date table for calculations and homework. You can right-click the image to download it or grab the PDF file of the periodic table.

Black and White Printable Periodic Table
New for 2019! This black and white printable periodic table is specially designed for middle school or high school use. It includes electron configurations, oxidation states, groups, periods, and more. Right-click the image to download it or grab the PDF file for printing.

Periodic Table for Kids
This 118 element printable periodic table is perfect for kids or anyone who wants a clean-looking chart with atomic weights rounded to the usual two decimal points. It's a lot less confusing for homework! This table is available in color, black/white, or as a PDF download.

Colored Periodic Table
This color periodic table is brightly colored and optimized to fit on a single sheet of paper. It has, along with the usual information, a legend square and numbered columns, and family names recommended by the IUPAC. [PDF]

Carina Nebula Periodic Table
This table is available as a poster, with the Carina Nebula (a photograph taken by the Hubble Space Telescope). [ JPG]

Element Charges Periodic Table
This printable table lists the most common charges or oxidation states carried by atoms of each element. The table is available in either black/white or color in PDF file or PNG image format. It contains the essential element facts, so you can use it as a standard periodic table just fine. [ black/white PDF][ color PDF]

Element Discovery Dates Periodic Table
Each element cell of this table cites the year in which that element was discovered. The coloring of the tiles groups elements according to the time periodic of their discovery. See if you can spot the first manmade element. Here's a hint: the element symbol starts with a "T". [ PNG on black][ PNG on white]

Periodic Table with Electron Shells
Tired of figuring out electron configurations or just want to check your work? This printable table shows element name, symbol, number, group, and also the filling of the electron shells. It's one of the most comprehensive periodic tables on the site.

Metals, Metalloids, and Nonmetals Periodic Table
This is a collection of printable periodic tables that show the metals, metalloids (semimetals), and nonmetals as well as the properties of these important element groups. The properties of these element groups are listed, too.

How To Use a Periodic Table
Learn how to read a periodic table. Now you have a periodic table, are you sure you know how to use it? Here's a look at the type of information you'll find on a typical periodic table and how to use it to answer questions about the elements.

Periodic Table Element Cells
This is a collection of individual element cells that you can save and print. Individual element cells are supplied as PNG files, You may also download the entire collection of elements as a PDF file. A few color variations are available, including a black and white set of tiles.

More Printable Periodic Tables

Here are some more periodic tables you can download or print. Some of these tables don't include the four most recently discovered elements, but it's not like you need those for calculations. Some of these tables are classics, while others feature cool artwork. If you see a table you like and want the additional data, post a comment and we can update it.

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Periodic Table Thumbnail

Periodic Table Description

Printable Periodic Table Without Names
This chart features the element symbols, atomic numbers, and atomic weights, but does not list the element names. You can use it to help learn to associate the names and symbols, like for quizzes and such. The color version of the table includes the element groups and a key, while the black and white version omits the groups, so you can learn those or color them in. PDFs files are available for both tables. [ color PDF][ black and white PDF]

Colored Bar Periodic Table
This chart has a black background with white text. Colored bars are used to distinguish between the element groups. We were aiming for a subtle rainbow effect here. This is a nice table for a screen saver or to look up information on a mobile device. Visit this table's page to get details about its features. It's easy on the eyes in a darkened room.

Futuristic Periodic Table WallpaperHere is another HD periodic table wallpaper for your desktop, laptop, or mobile device. This one features translucent element tiles and a space-theme background. We like this one as a monitor screensaver. Open the image and right-click to save it to your device.

Fireworks Periodic Table
The fireworks periodic table shows which elements are important in fireworks and pyrotechnics. It's color coded, too.

Periodic Table Optimized for Printing
You can print any of these tables (just select "print to fit"), but this particular set of tables was specially designed to look great on regular printer paper. The tables maximize the available space on a sheet of paper, so you get the easiest-to-read printed version. Other printer-optimized tables are also available:

Glowing Text Periodic Table
New for 2019! These printable periodic tables appear to be glowing, like they were drawn using highlighters, or slightly radioactive, depending on the color you choose. The tables print up nicely, but where they really shine is as computer or phone wallpapers. Color options include glowing rad red, va-va-voom violet, glistening gold, green blue, and vivid yellow.

Black and White Printable Table - Negative Colors
This negative-colored periodic table contains essential information, such as element names, element symbols, atomic number, atomic mass, and element group. Although it's not something you'd probably want to print, it's very easy to read on a screen, such as on your phone or computer. In fact, it's our favorite table for mobile. If you don't like the black with white text, there is a regular black and white or color version.

Neon Periodic Table
This is a color printable periodic table with a neon color scheme. The neon effect borders the cells, leaving the element tiles clear so you can read the text. The table is available as either a png image file or as a PDF with either a transparent background or a black background. The colors really pop on a monitor or phone.

Colorful Periodic Table
This is another colorful periodic table. It has a cheery color scheme, making a rainbow from the alkali metals over to the noble gases. It's also available with a black background or as a PDF file. As always, it includes essential element facts needed to study chemistry and make calculations. We put a gap between the element cells to make the chart easy to read.

Original Printable Periodic Table
This is the original periodic table at Science Notes and About.com Chemistry (now ThoughtCo.com). It's not as accurate as the newer printable periodic tables given here because it doesn't have the data for the four newest elements, but a lot of you request it.

Early Muted Colors Periodic Tables
Relax with a muted color printable periodic table that's easy on the eyes, so you can have pretty colors and still read the data clearly. They make a rainbow! The table is available with a transparent background (appears white, but it's actually clear) or a black background. It includes all the usual essential element data: element groups, atomic numbers, atomic weights, symbols, and element names. The element group key is posted directly below the periodic table.

Printing Instructions for the Printable Periodic Tables

You can either print the HD image file (PNG) or else you can open and print the PDF files. It's a simple matter to spread out the image over several pages to make a large wall poster, too. We recommend you print the PDF files because they are made for that purpose!

Special Requests

Would you like to see a different color scheme, the periodic table in a different language, a periodic table for a particular holiday, or the element groups assigned differently? Let us know and we'll make up a table for you!

Printable Periodic Tables Terms of Use

Please feel free to print these tables for personal use and to hand out to students. You can post them in your classroom, lab, kitchen, etc. and display them on your phone and computer. You may not copy and post the periodic tables on your own website. You may not sell them or adapt them to sell.

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Free Printable Periodic Tables (PDF and PNG) - Science Notes and Projects

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A printable periodic table is an essential tool for students and chemists. You can place it where you need it while solving problems, mark it up, and print a new one whenever you like. This is a collection of free printable periodic tables in PDF file or PNG image format to save, print, and use.

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Why We Are Made of "Star Stuff" | Reactions Science Videos - American Chemical Society

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As Carl Sagan famously said, "We are made of star stuff." Whoa. It's a mind-boggling thought, but what exactly did he mean?

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Bookmarks (padlet.com)