# data[].attributes.body
This is an engaging way to do the chromatography experiment. The students can work in groups to solve the case, answering the questions at the end to conclude.  This is also relatable to real life experiences as this is how forensic scientists work.

# data[].attributes.body
This helps the students to visualise the atomic nature of a solid, a liquid and a gas.

# data[].attributes.body
This video connects chromatography to real life experiences which I think the students find interesting.

# data[].attributes.attachment_link.title
1.4 - Brian Cox School experiments - Filtration

# data[].attributes.body
This article emphasised the importance of modelling to provide explanations, generate discussions and make predictions. Models are genius as they help us to explore a concept too small to see. This article also brought to light the issue of the accuracy of the representations, indicating that they are not real but they represent. I incorporated models into my unit by asking the students to draw their representation of the particles of the three states of matter, ensuing to make them as accurate as possible.

# data[].attributes.body
This a breakdown of the key skills incorporated throughout my planning.

# data[].attributes.body
The first image allows the students to differentiate between a physical or chemical change using practical examples. This leads nicely onto the concept of Conservation of Mass. The video summarises changes in states, linking it with physical vs. chemical changes.

# data[].attributes.body
This activity is very useful to summarise what the students have learned. It includes all the aspects of this LO and can be beneficial to check that the learning intentions are met.

# data[].attributes.headline
Chemical vs. Physical changes activity: 

# data[].attributes.subject
Chemical vs. Physical changes activity: 

# data[].attributes.body
This activity is an engaging way to do physical vs chemical changes. The students can stick this into their notes copy as a reference. It also links with the properties of material in CW6.

# data[].attributes.body
I took an 'inquiry- based' outlook when creating my unit. I encouraged the students work like scientist in generating hypotheses, investigating them and drawing conclusions from the data collected. This then ensured that the students were actively engaged throughout each lesson.

# data[].attributes.body
This paper highlighted the importance of bringing epistemic agency into the classroom. I set manageable goals for the students in the learning intentions and sharing them with the students ensured that they could monitor their progress. I eliminated rote learning from my unit and encouraged the construction of knowledge by asking open- ended questions. I also incorporated opportunities for the students to build on any new ideas they had and to learn independently.

# data[].attributes.body
The students completed this as homework to recap on what they had learned from doing the experiment.

# data[].attributes.body
I used this resource to deepen my knowledge of separation the different separation techniques.

# data[].attributes.attachment_link.description
The basic objectives of this book are to: provide basic information on chromatography and separation science; show how simple extraction and partition processes provide the basis for development of chromatography and separation science; describe the role of chromatography and separation science in various fields; discuss the role of chromatography and separation science in development of new methodology; and present new evolving methods and how to select an optimum method.

# data[].attributes.body
I used this quiz to fill in 'dead time' for the students while I was showing another group a distillation process.

# data[].attributes.headline
An example of a task and student work -NCCA website

# data[].attributes.subject
An example of a task and student work -NCCA website

# data[].attributes.body
This task takes a different approach to the states of matter in creating a magazine article. The conservation of mass or different separation techniques could be brought in here also.

# data[].attributes.attachment_link.readable_text
Resource type: Student Work

First Year sample judged In Line With Expectations. Students write an article for the science section in the school magazine communicating the types of matter that can exist in a clear, humorous and fact based manner.

You can find the PDF here.

# data[].attributes.attachment_link.description
Resource type: Student Work First Year sample judged In Line With Expectations. Students write an article for the science section in the school magazine communicating the types of matter that can exist in a clear, humorous and fact based manner. You can find the PDF here.

# data[].attributes.body
This video helps to explain how the salt dissolves/ 'disappears' in water prior to the evaporation.

# data[].attributes.body
This worksheet allows the students to draw the particles of a solid, liquid and gas. This will benefit the students when representing what is happening before, during and after evaporation. Heat loss and gain can be added in also which will help in explaining conservation of matter.

# data[].attributes.attachment_link.readable_text
Monday, January 13, 2020

Matter makes up everything visible in the known universe, from port-a-potties to supernovas. And because matter is never created or destroyed, it cycles through our world. Atoms that were in a dinosaur millions of years ago-and in a star billions of years before that-may be inside you today.

Matter is anything that has mass and takes up space. It includes molecules, atoms, fundamental particles, and any substance that these particles make up. Matter can change form through physical and chemical changes, but through any of these changes matter is conserved. The same amount of matter exists before and after the change-none is created or destroyed. This concept is called the Law of Conservation of Mass.

In a physical change, a substance's physical properties may change, but its chemical makeup does not. Water, for example, is made up of two hydrogen atoms and one oxygen atom. Water is the only known substance on Earth that exists naturally in three states: solid, liquid, and gas. To change between these states, water must undergo physical changes. When water freezes, it becomes hard and less dense, but it is still chemically the same. There are the same number of water molecules present before and after the change, and water's chemical properties remain constant.

To form water, however, hydrogen and oxygen atoms must undergo chemical changes. or a chemical change to occur, atoms must either break bonds and/or form bonds. The addition or subtraction of atomic bonds changes the chemical properties of the substances involved. Both hydrogen and oxygen are diatomic-they exist naturally as bonded pairs (H ₂ and O ₂, respectively). In the right conditions and with enough energy, these diatomic bonds will break and the atoms will join to form H ₂ O (water). Chemists write out this chemical reaction as:

This equation says that it takes two molecules of hydrogen and one molecule of oxygen to form two molecules of water. Notice that there are the same number of hydrogen atoms and oxygen atoms on either side of the equation. In chemical changes, just as in physical changes, matter is conserved. The difference, in this case, is that the substances before and after the change have different physical and chemical properties. Hydrogen and oxygen are gases at standard temperature and pressure, whereas water is a colorless, odorless liquid.

Ecosystems have many chemical and physical changes happening all at once, and matter is conserved in each and every one - no exceptions. Consider a stream flowing through a canyon - how many chemical and physical changes are happening at any given moment?

First, let's consider the water. For many canyon streams, the water comes from higher elevations and originates as snow. Of course, that's not where the water began-it's been cycled all over the world since Earth first had water. But in the context of the canyon stream, it began in the mountains as snow. The snow must undergo a physical change-melting-to join the stream. As the liquid water flows through the canyon, it may evaporate (another physical change) into water vapor. Water gives a very clear example of how matter cycles through our world, frequently changing form but never disappearing.

Next, consider the plants and algae living in and along the stream. In a process called photosynthesis, these organisms convert light energy from the sun into chemical energy stored in sugars. However, the light energy doesn't produce the atoms that make up those sugars-that would break the Law of Conservation of Mass-it simply provides energy for a chemical change to occur. The atoms come from carbon dioxide in the air and water in the soil. Light energy allows these bonds to break and reform to produce sugar and oxygen, as shown in the chemical equation for photosynthesis:

This equation says that six carbon dioxide molecules combine with six water molecules to form one sugar molecule and six molecules of oxygen. If you added up all the carbon, hydrogen, and oxygen atoms on either side of the equation, the sums would be equal; matter is conserved in this chemical change.

When animals in and around the stream eat these plants, their bodies use the stored chemical energy to power their cells and move around. They use the nutrients in their food to grow and repair their bodies-the atoms for new cells must come from somewhere. Any food that enters an animal's body must either leave its body or become part of it; no atoms are destroyed or created.

Matter is also conserved during physical and chemical changes in the rock cycle. As a stream carves deeper into a canyon, the rocks of the canyon floor don't disappear. They're eroded by the stream and carried off in small bits called sediments. These sediments may settle at the bottom of a lake or pond at the end of the stream, building up in layers over time. The weight of each additional layer compacts the layers beneath it, eventually adding so much pressure that new sedimentary rock forms. This is a physical change for the rock, but with the right conditions, the rock may chemically change too. In either case, the matter in the rock is conserved.

The bottom line is: Matter cycles through the universe in many different forms. In any physical or chemical change, matter doesn't appear or disappear. Atoms created in the stars (a very, very long time ago) make up every living and nonliving thing on Earth-even you. It's impossible to know how far and through what forms your atoms traveled to make you. And it's impossible to know where they will end up next.

This isn't the whole story of matter, however, it's the story of visible matter. Scientists have learned that about 25 percent of the universe's mass consists of dark matter-matter that cannot be seen but can be detected through its gravitational effects. The exact nature of dark matter has yet to be determined. Another 70 percent of the universe is an even more mysterious component called dark energy, which acts counter to gravity. So "normal" matter makes up, at most, five percent of the universe.

# data[].attributes.attachment_link.title
The Conservation of Matter During Physical and Chemical Changes

# data[].attributes.attachment_link.description
Monday, January 13, 2020 Matter makes up everything visible in the known universe, from port-a-potties to supernovas. And because matter is never created or destroyed, it cycles through our world. Atoms that were in a dinosaur millions of years ago-and in a star billions of years before that-may be inside you today.

# data[].attributes.body
This clip gives a practical and simple explanation of the conservation of mass. Students could observe conservation of mass by investigating using vinegar and baking soda in a seal-able plastic bag.

# data[].attributes.attachment_link.title
Vacation or Conservation (Of Mass): Crash Course Kids #23.1

# data[].attributes.headline
What do students struggle with in understanding evaporation.  

# data[].attributes.subject
What do students struggle with in understanding evaporation.  

# data[].attributes.body
The concept of 'disappearing' or 'dissolving' needs to be explained and can be done using a basic particle model.

# data[].attributes.attachment_link.readable_text
Evaporation and condensation are two particularly difficult concepts for students to understand, especially young students who have not yet learned about atoms and molecules. To these learners, evaporation happens when water dries up or disappears. These students do not have a better way of explaining what happens to the water, so they default to explaining that the water disappears. Teaching about evaporation or other water-cycle processes can be particularly difficult because students can only see the visible parts of the process but not what is occurring at the molecular level. Evaporation, however, is an important process that brings freshwater to natural and human communities, and all students should understand how this happens and why it is important to our survival.

Watch this video of 3rd grade students in Auburn, California-an inland community. The purpose of this classroom video is to hear and think about student ideas about evaporation and how best to teach this concept.

For additional classroom context, video analysis, and reflection opportunities, read the Picture of Practice page for "Learning About Evaporation" in the Earth's Freshwater Environmental Literacy Teacher Guide, page 35.

Credits

Media Credits

The audio, illustrations, photos, and videos are credited beneath the media asset, except for promotional images, which generally link to another page that contains the media credit. The Rights Holder for media is the person or group credited.

Writers

Ari J. Posner, M.S. Urban Planning
Lindsey Mohan, Ph.D. Educational Psychology and Technology
Sandra Postel, National Geographic Fellow
Tara G. Treiber, B.A. Natural Sciences: Ecology
Beth A. Covitt, Ph.D. Environmental Education and Conservation Psychology
Tania T. Hinojosa, M.Ed. Educational Technology
Jose Marcos-Iga, Ph.D. Natural Resources
Marcia S. Matz, M.A. Design
Abraham Miller-Rushing, Ph.D. Biology
Anica Miller-Rushing, M.Ed. Curriculum and Instruction

Designer

Cindy Olson

Editors

Kristen Dell, National Geographic Society
Lindsey Mohan, Ph.D.
Chelsea Zillmer

Educator Reviewers

Catie Boarts, Heal the Bay
Beth A. Covitt, University of Montana
Jenny D. Ingber
Meghan E. Marrero, New York State Marine Education
Marcia S. Matz
Sandra Postel, National Geographic Fellow

Last Updated

Feb. 27, 2013

User Permissions

For information on user permissions, please read our Terms of Service. If you have questions about licensing content on this page, please contact ngimagecollection@natgeo.com for more information and to obtain a license. If you have questions about how to cite anything on our website in your project or classroom presentation, please visit our FAQ page.

Media

If a media asset is downloadable, a download button appears in the corner of the media viewer. If no button appears, you cannot download or save the media.

Text

Text on this page is printable and can be used according to our Terms of Service.

Interactives

Any interactives on this page can only be played while you are visiting our website. You cannot download interactives.

# data[].attributes.attachment_link.description
Evaporation and condensation are two particularly difficult concepts for students to understand, especially young students who have not yet learned about atoms and molecules. To these learners, evaporation happens when water dries up or disappears. These students do not have a better way of explaining what happens to the water, so they default to explaining that the water disappears.

# data[].attributes.body
2. Students should be able to develop and use models to describe the atomic nature of matter; demonstrate how they provide a simple way to account for the conservation of mass, changes of state, physical change, chemical change, mixtures and their separation.

# data[].attributes.body
This is a lesson I taught on evaporation.

# data[].attributes.body
The first learning outcome of this unit links with the CW2 LO.

# data[].attributes.body
NoS 1- Students appreciate how scientists work.
NoS 2- Students are introduced to developing their own hypotheses for investigating conservation of mass and evaporation.
NoS 3- Students are designing their own experiments, planning them, and preforming them to test their hypotheses they generated.
NoS 4-  Students are differentiating between qualitative and quantitative data during every experiment. They also have to draw up their own conclusions.
CW1 - Students would have to have touched on this LO in order to comprehend the conservation of mass. Mass is covered here and it also links in with physical and chemical changes.
CW 4- Students are classifying solids, liquids and gases in order to draw the particle representation of each of them.