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A

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0 c go to model z 0 c go to model z 23 c go to model x 5 c and 7 c model y .

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hot plate off low pressure hot plate set to 60 C medium pressure hot plate set to 120 C high pressure.

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B

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B

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0 c to the right is model z
0 c to the left is y
5 c is x

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The first one one will be low because if you look at it there is not any type of occur in the pic . The second one will be medium because it has a little bit of bubbles and a lil bit of smoke to . The last one will be high because in the pic it has the highest temp and the burner is the rudest it has more bubbles and smoke that had occurred.

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B

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B

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B

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0 to the right is model Z
0 to the left is model X
23 is model Y

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0 c to the left is y
0 c to the right is z
23 c at the top is x

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B

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A

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Its b because it has the more changes .

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First plate is low temperature, Second plate is medium temperature, and Third plate is high temperature.

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B

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B

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a

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b

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Hot play off is low pressure
hot play set 60 is medium pressure
hot play 120 is high pressure

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Particle Motion & Energy Transfer - Mrs. Sybert's Class

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Particle Motion & Energy Transfer - Mrs. Sybert's Class

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The one that say ¨hot plate off¨ is at a low temperature because it is at room temperature.
The second one that says ¨hot plate set to 60 degree Celsius¨ it is at a medium temperature because it is getting higher in temperature.
The last one that says ¨hot plate set to 120 degree Celsius is at the highest temperature because it is at its highest point.

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Its the second one because you can tell when zinc sulfide happens when the color and melting point is different.

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first plate has a low temperature the second plate has a medium temperature and the third plate has a high temperature

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A

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i pick B because if you just mix sugar and water the sugar is just gonna disolve

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B

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When a mixture of zinc and sulfur is heated, a chemical reaction does occurs. This is supported by the data in the table showing that zinc sulfide is a different color, and sulfur has the lowest melting point. During the process, the zinc and sulfur atoms, rearrange to form new molecules.

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It is B because when oxygen and rearrange to form a combination a molecules.

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B

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B

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0 c to the right is  model z
0 c to the left is y
5 c is x

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When a mixture of zine and sulfur is heated, a chemical reaction does occurs. This is supported by the data in the table showing that zine sulfur is a different color. During this process, the zine and sulfur atoms rearrange to form new molecules.

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It is Beaker 2 because it had a changes and Beaker 1 did not have any changes at all.

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The one that say hot play off has nothing going on. The one that say hot plate set to 60.C has a little bubbles coming out of it so basically it has water that forming into bubbles and going into the air. The one that say hot plate set to 120.C as allot of stuff to do with it because it has tons of bubble coming out of it so it's basically a lot of gas coming out of the cup or whatever you wanna call it.

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B because it had more changes

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First plate is low temperature
Second plate is medium temperature
Third plate is high tepreature.

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B

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B

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Its the second answer because a chemical reactions happens

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It is the second one because a chemical reaction occurs .

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It is a the second one because when a chemical reaction occurs when a change between two substance form into a new sub

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Chemical Changes: Crash Course Kids #19.2 - YouTube

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Chemical Changes: Crash Course Kids #19.2 - YouTube

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Chemical Changes: Crash Course Kids #19.2

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Chemical Equation for Baking Soda and Vinegar Reaction

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Chapter 5 Lecture Notes
Learning Objectives

By the end of this section, you will be able to:

Define energy, distinguish types of energy, and describe the nature of energy changes that accompany chemical and physical changes

Distinguish the related properties of heat, thermal energy, and temperature

Define and distinguish specific heat and heat capacity, and describe the physical implications of both

Perform calculations involving heat, specific heat, and temperature change

Chemical changes and their accompanying changes in energy are important parts of our everyday world (Figure 1). The macronutrients in food (proteins, fats, and carbohydrates) undergo metabolic reactions that provide the energy to keep our bodies functioning. We burn a variety of fuels (gasoline, natural gas, coal) to produce energy for transportation, heating, and the generation of electricity. Industrial chemical reactions use enormous amounts of energy to produce raw materials (such as iron and aluminum). Energy is then used to manufacture those raw materials into useful products, such as cars, skyscrapers, and bridges.

Over 90% of the energy we use comes originally from the sun. Every day, the sun provides the earth with almost 10,000 times the amount of energy necessary to meet all of the world's energy needs for that day. Our challenge is to find ways to convert and store incoming solar energy so that it can be used in reactions or chemical processes that are both convenient and nonpolluting. Plants and many bacteria capture solar energy through photosynthesis. We release the energy stored in plants when we burn wood or plant products such as ethanol. We also use this energy to fuel our bodies by eating food that comes directly from plants or from animals that got their energy by eating plants. Burning coal and petroleum also releases stored solar energy: These fuels are fossilized plant and animal matter.

This chapter will introduce the basic ideas of an important area of science concerned with the amount of heat absorbed or released during chemical and physical changes-an area called thermochemistry. The concepts introduced in this chapter are widely used in almost all scientific and technical fields. Food scientists use them to determine the energy content of foods. Biologists study the energetics of living organisms, such as the metabolic combustion of sugar into carbon dioxide and water. The oil, gas, and transportation industries, renewable energy providers, and many others endeavor to find better methods to produce energy for our commercial and personal needs. Engineers strive to improve energy efficiency, find better ways to heat and cool our homes, refrigerate our food and drinks, and meet the energy and cooling needs of computers and electronics, among other applications. Understanding thermochemical principles is essential for chemists, physicists, biologists, geologists, every type of engineer, and just about anyone who studies or does any kind of science.

Energy

Energy can be defined as the capacity to supply heat or do work. One type of is the process of causing matter to move against an opposing force. For example, we do work when we inflate a bicycle tire-we move matter (the air in the pump) against the opposing force of the air already in the tire.

Like matter, energy comes in different types. One scheme classifies energy into two types: potential energy, the energy an object has because of its relative position, composition, or condition, and kinetic energy, the energy that an object possesses because of its motion. Water at the top of a waterfall or dam has potential energy because of its position; when it flows downward through generators, it has kinetic energy that can be used to do work and produce electricity in a hydroelectric plant (Figure 2). A battery has potential energy because the chemicals within it can produce electricity that can do work.

Energy can be converted from one form into another, but all of the energy present before a change occurs always exists in some form after the change is completed. This observation is expressed in the law of conservation of energy: during a chemical or physical change, energy can be neither created nor destroyed, although it can be changed in form. (This is also one version of the first law of thermodynamics, as you will learn later.)

When one substance is converted into another, there is always an associated conversion of one form of energy into another. Heat is usually released or absorbed, but sometimes the conversion involves light, electrical energy, or some other form of energy. For example, chemical energy (a type of potential energy) is stored in the molecules that compose gasoline. When gasoline is combusted within the cylinders of a car's engine, the rapidly expanding gaseous products of this chemical reaction generate mechanical energy (a type of kinetic energy) when they move the cylinders' pistons.

According to the law of conservation of matter (seen in an earlier chapter), there is no detectable change in the total amount of matter during a chemical change. When chemical reactions occur, the energy changes are relatively modest and the mass changes are too small to measure, so the laws of conservation of matter and energy hold well. However, in nuclear reactions, the energy changes are much larger (by factors of a million or so), the mass changes are measurable, and matter-energy conversions are significant. This will be examined in more detail in a later chapter on nuclear chemistry. To encompass both chemical and nuclear changes, we combine these laws into one statement: The total quantity of matter and energy in the universe is fixed.

Thermal Energy, Temperature, and Heat

Thermal energy is kinetic energy associated with the random motion of atoms and molecules. Temperature is a quantitative measure of "hot" or "cold." When the atoms and molecules in an object are moving or vibrating quickly, they have a higher average kinetic energy (KE), and we say that the object is "hot." When the atoms and molecules are moving slowly, they have lower KE, and we say that the object is "cold" (Figure 3). Assuming that no chemical reaction or phase change (such as melting or vaporizing) occurs, increasing the amount of thermal energy in a sample of matter will cause its temperature to increase. And, assuming that no chemical reaction or phase change (such as condensation or freezing) occurs, decreasing the amount of thermal energy in a sample of matter will cause its temperature to decrease.

Most substances expand as their temperature increases and contract as their temperature decreases. This property can be used to measure temperature changes, as shown in Figure 4. The operation of many thermometers depends on the expansion and contraction of substances in response to temperature changes.

Heat (q) is the transfer of thermal energy between two bodies at different temperatures. Heat flow (a redundant term, but one commonly used) increases the thermal energy of one body and decreases the thermal energy of the other. Suppose we initially have a high temperature (and high thermal energy) substance (H) and a low temperature (and low thermal energy) substance (L). The atoms and molecules in H have a higher average KE than those in L. If we place substance H in contact with substance L, the thermal energy will flow spontaneously from substance H to substance L. The temperature of substance H will decrease, as will the average KE of its molecules; the temperature of substance L will increase, along with the average KE of its molecules. Heat flow will continue until the two substances are at the same temperature (Figure 5).

Click on the PhET simulation to explore energy forms and changes. Visit the Energy Systems tab to create combinations of energy sources, transformation methods, and outputs. Click on Energy Symbols to visualize the transfer of energy.

Matter undergoing chemical reactions and physical changes can release or absorb heat. A change that releases heat is called an exothermic process. For example, the combustion reaction that occurs when using an oxyacetylene torch is an exothermic process-this process also releases energy in the form of light as evidenced by the torch's flame (Figure 6). A reaction or change that absorbs heat is an endothermic process. A cold pack used to treat muscle strains provides an example of an endothermic process. When the substances in the cold pack (water and a salt like ammonium nitrate) are brought together, the resulting process absorbs heat, leading to the sensation of cold.

Historically, energy was measured in units of calories (cal). A calorie is the amount of energy required to raise one gram of water by 1 degree C (1 kelvin). However, this quantity depends on the atmospheric pressure and the starting temperature of the water. The ease of measurement of energy changes in calories has meant that the calorie is still frequently used. The Calorie (with a capital C), or large calorie, commonly used in quantifying food energy content, is a kilocalorie. The SI unit of heat, work, and energy is the joule. A joule (J) is defined as the amount of energy used when a force of 1 newton moves an object 1 meter. It is named in honor of the English physicist James Prescott Joule. One joule is equivalent to 1 kg m ²/s ², which is also called 1 newton-meter. A kilojoule (kJ) is 1000 joules. To standardize its definition, 1 calorie has been set to equal 4.184 joules.

We now introduce two concepts useful in describing heat flow and temperature change. The heat capacity (C) of a body of matter is the quantity of heat ( q) it absorbs or releases when it experiences a temperature change (Δ T) of 1 degree Celsius (or equivalently, 1 kelvin):

[latex]\displaystyle{C}=\frac{q}{\Delta T}[/latex]

Heat capacity is determined by both the type and amount of substance that absorbs or releases heat. It is therefore an extensive property-its value is proportional to the amount of the substance.

For example, consider the heat capacities of two cast iron frying pans. The heat capacity of the large pan is five times greater than that of the small pan, because, although both are made of the same material, the mass of the large pan is five times greater than the mass of the small pan. More mass means more atoms are present in the larger pan, so it takes more energy to make all of those atoms vibrate faster. The heat capacity of the small cast iron frying pan is found by observing that it takes 18,150 J of energy to raise the temperature of the pan by 50.0 °C:

[latex]{C}_{\text{small pan}}=\frac{\text{18,140 J}}{50.0^{\circ}\text{ C}}=363\text{ J/}^{\circ}\text{C}[/latex]

The larger cast iron frying pan, while made of the same substance, requires 90,700 J of energy to raise its temperature by 50.0 °C. The larger pan has a (proportionally) larger heat capacity, because the larger amount of material requires a (proportionally) larger amount of energy to yield the same temperature change:

[latex]{C}_{\text{large pan}}=\frac{\text{90,700 J}}{50.0^{\circ}\text{ C}}=1814\text{ J/}^{\circ}\text{C}[/latex]

The specific heat capacity (c) of a substance, commonly called its "specific heat," is the quantity of heat required to raise the temperature of 1 gram of a substance by 1 degree Celsius (or 1 kelvin):

[latex]\displaystyle{c}=\frac{q}{\text{m}\Delta\text{T}}[/latex]

Specific heat capacity depends only on the kind of substance absorbing or releasing heat. It is an intensive property-the type, but not the amount, of the substance is all that matters. For example, the small cast iron frying pan has a mass of 808 g. The specific heat of iron (the material used to make the pan) is therefore:

[latex]\displaystyle{c}_{\text{iron}}=\frac{\text{18,140 J}}{\left(\text{808 g}\right)\left(50.0^{\circ}\text{ C}\right)=\text{0.449 J/g}^{\circ}\text{ C}}[/latex]

The large frying pan has a mass of 4040 g. Using the data for this pan, we can also calculate the specific heat of iron:

[latex]\displaystyle{c}_{\text{iron}}=\frac{\text{90,700 J}}{\left(\text{4040 g}\right)\left(50.0^{\circ}\text{ C}\right)=\text{0.449 J/g}^{\circ}\text{ C}}[/latex]

Although the large pan is more massive than the small pan, since both are made of the same material, they both yield the same value for specific heat (for the material of construction, iron). Note that specific heat is measured in units of energy per temperature per mass and is an intensive property, being derived from a ratio of two extensive properties (heat and mass). The molar heat capacity, also an intensive property, is the heat capacity per mole of a particular substance and has units of J/mol °C (Figure 7).

Liquid water has a relatively high specific heat (about 4.2 J/g °C); most metals have much lower specific heats (usually less than 1 J/g °C). The specific heat of a substance varies somewhat with temperature. However, this variation is usually small enough that we will treat specific heat as constant over the range of temperatures that will be considered in this chapter. Specific heats of some common substances are listed in Table 1.

If we know the mass of a substance and its specific heat, we can determine the amount of heat, q, entering or leaving the substance by measuring the temperature change before and after the heat is gained or lost:

[latex]\begin{array}{l}q=\left(\text{specific heat}\right)\times \left(\text{mass of substance}\right)\times \left(\text{temperature change}\right)\\ q=c\times m\times \Delta\text{T}=c\times m\times \left({T}_{\text{final}}-{T}_{\text{initial}}\right)\end{array}[/latex]

In this equation, c is the specific heat of the substance, m is its mass, and Δ T (which is read "delta T") is the temperature change, T final - T initial. If a substance gains thermal energy, its temperature increases, its final temperature is higher than its initial temperature, T final - T initial has a positive value, and the value of q is positive. If a substance loses thermal energy, its temperature decreases, the final temperature is lower than the initial temperature, T final - T initial has a negative value, and the value of q is negative.

Example 1: Measuring Heat

A flask containing 8.0 × 10 ² g of water is heated, and the temperature of the water increases from 21 °C to 85 °C. How much heat did the water absorb?

Check Your Learning

How much heat, in joules, must be added to a 5.00 × 10 ²-g iron skillet to increase its temperature from 25 °C to 250 °C? The specific heat of iron is 0.451 J/g °C

Note that the relationship between heat, specific heat, mass, and temperature change can be used to determine any of these quantities (not just heat) if the other three are known or can be deduced.

Example 2: Determining Other Quantities

A piece of unknown metal weighs 348 g. When the metal piece absorbs 6.64 kJ of heat, its temperature increases from 22.4 °C to 43.6 °C. Determine the specific heat of this metal (which might provide a clue to its identity).

Check Your Learning

A piece of unknown metal weighs 217 g. When the metal piece absorbs 1.43 kJ of heat, its temperature increases from 24.5 °C to 39.1 °C. Determine the specific heat of this metal, and predict its identity.

Exercises

Most people find waterbeds uncomfortable unless the water temperature is maintained at about 85 °F. Unless it is heated, a waterbed that contains 892 L of water cools from 85 °F to 72 °F in 24 hours. Estimate the amount of electrical energy required over 24 hours, in kWh, to keep the bed from cooling. Note that 1 kilowatt-hour (kWh) = 3.6 × 10 ⁶ J, and assume that the density of water is 1.0 g/mL (independent of temperature). What other assumptions did you make? How did they affect your calculated result (i.e., were they likely to yield "positive" or "negative" errors)?

Solar Thermal Energy Power Plants

The sunlight that reaches the earth contains thousands of times more energy than we presently capture. Solar thermal systems provide one possible solution to the problem of converting energy from the sun into energy we can use. Large-scale solar thermal plants have different design specifics, but all concentrate sunlight to heat some substance; the heat "stored" in that substance is then converted into electricity.

The Solana Generating Station in Arizona's Sonora Desert produces 280 megawatts of electrical power. It uses parabolic mirrors that focus sunlight on pipes filled with a heat transfer fluid (HTF) (Figure 8). The HTF then does two things: It turns water into steam, which spins turbines, which in turn produces electricity, and it melts and heats a mixture of salts, which functions as a thermal energy storage system. After the sun goes down, the molten salt mixture can then release enough of its stored heat to produce steam to run the turbines for 6 hours. Molten salts are used because they possess a number of beneficial properties, including high heat capacities and thermal conductivities.

The 377-megawatt Ivanpah Solar Generating System, located in the Mojave Desert in California, is the largest solar thermal power plant in the world (Figure 9). Its 170,000 mirrors focus huge amounts of sunlight on three water-filled towers, producing steam at over 538 °C that drives electricity-producing turbines. It produces enough energy to power 140,000 homes. Water is used as the working fluid because of its large heat capacity and heat of vaporization.

Key Concepts and Summary

Energy is the capacity to do work (applying a force to move matter). Kinetic energy (KE) is the energy of motion; potential energy is energy due to relative position, composition, or condition. When energy is converted from one form into another, energy is neither created nor destroyed (law of conservation of energy or first law of thermodynamics).

Matter has thermal energy due to the KE of its molecules and temperature that corresponds to the average KE of its molecules. Heat is energy that is transferred between objects at different temperatures; it flows from a high to a low temperature. Chemical and physical processes can absorb heat (endothermic) or release heat (exothermic). The SI unit of energy, heat, and work is the joule (J).

Specific heat and heat capacity are measures of the energy needed to change the temperature of a substance or object. The amount of heat absorbed or released by a substance depends directly on the type of substance, its mass, and the temperature change it undergoes.

Key Equations

[latex]q=c\times m\times \Delta\text{T}=c\times m\times \left({T}_{\text{final}}-{T}_{\text{initial}}\right)[/latex]

Exercises

1. A burning match and a bonfire may have the same temperature, yet you would not sit around a burning match on a fall evening to stay warm. Why not?

2. Prepare a table identifying several energy transitions that take place during the typical operation of an automobile.

3. Explain the difference between heat capacity and specific heat of a substance.

4. Calculate the heat capacity, in joules and in calories per degree, of the following:

1. 28.4 g of water

2. 1.00 oz of lead

5. Calculate the heat capacity, in joules and in calories per degree, of the following:

1. 45.8 g of nitrogen gas

2. 1.00 pound of aluminum metal

6. How much heat, in joules and in calories, must be added to a 75.0-g iron block with a specific heat of 0.449 J/g °C to increase its temperature from 25 °C to its melting temperature of 1535 °C?

7. How much heat, in joules and in calories, is required to heat a 28.4-g (1-oz) ice cube from -23.0 °C to -1.0 °C?

8. How much would the temperature of 275 g of water increase if 36.5 kJ of heat were added?

9. If 14.5 kJ of heat were added to 485 g of liquid water, how much would its temperature increase?

10. A piece of unknown substance weighs 44.7 g and requires 2110 J to increase its temperature from 23.2 °C to 89.6 °C.

1. What is the specific heat of the substance?

2. If it is one of the substances found in Table 1, what is its likely identity?

11. A piece of unknown solid substance weighs 437.2 g, and requires 8460 J to increase its temperature from 19.3 °C to 68.9 °C.

1. What is the specific heat of the substance?

2. If it is one of the substances found in Table 1, what is its likely identity?

12. An aluminum kettle weighs 1.05 kg.

1. What is the heat capacity of the kettle?

2. How much heat is required to increase the temperature of this kettle from 23.0 °C to 99.0 °C?

3. How much heat is required to heat this kettle from 23.0 °C to 99.0 °C if it contains 1.25 L of water (density of 0.997 g/mL and a specific heat of 4.184 J/g °C)?

Glossary

calorie (cal): unit of heat or other energy; the amount of energy required to raise 1 gram of water by 1 degree Celsius; 1 cal is defined as 4.184 J

endothermic process: chemical reaction or physical change that absorbs heat

energy: capacity to supply heat or do work

exothermic process: chemical reaction or physical change that releases heat

heat (q): transfer of thermal energy between two bodies

heat capacity (C): extensive property of a body of matter that represents the quantity of heat required to increase its temperature by 1 degree Celsius (or 1 kelvin)

joule (J): SI unit of energy; 1 joule is the kinetic energy of an object with a mass of 2 kilograms moving with a velocity of 1 meter per second, 1 J = 1 kg m ²/s and 4.184 J = 1 cal

kinetic energy: energy of a moving body, in joules, equal to [latex]\frac{1}{2}m{v}^{2}[/latex] (where m = mass and v = velocity)

potential energy: energy of a particle or system of particles derived from relative position, composition, or condition

specific heat capacity (c): intensive property of a substance that represents the quantity of heat required to raise the temperature of 1 gram of the substance by 1 degree Celsius (or 1 kelvin)

temperature: intensive property of matter that is a quantitative measure of "hotness" and "coldness;" it is related to the average kinetic energy of the atoms or molecules that make up the object

thermal energy: kinetic energy associated with the random motion of atoms and molecules

thermochemistry: study of measuring the amount of heat absorbed or released during a chemical reaction or a physical change

work (w): energy transfer due to changes in external, macroscopic variables such as pressure and volume; or causing matter to move against an opposing force

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Chapter 5 Lecture Notes By the end of this section, you will be able to: Define energy, distinguish types of energy, and describe the nature of energy changes that accompany chemical and physical changes Distinguish the related properties of heat, thermal energy, and temperature Define and distinguish specific heat and heat capacity, and describe the physical implications of both Perform calculations involving heat, specific heat, and temperature change Chemical changes and their accompanying changes in energy are important parts of our everyday world (Figure 1).

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Physical and Chemical Properties of Matter | Boundless Chemistry

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Properties of matter can be classified as either extensive or intensive and as either physical or chemical.

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Physical and Chemical Properties of Matter

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the type of matter effect's the temperature of a substance because not all matter has the same temperature all the time. For exaple, a rock and a boiling egg they are both solids but , they both have different temperatures the boiling egg is hot but the rock is cold.

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Welcome to the Chemistry Library. This Living Library is a principal hub of the LibreTexts project, which is a multi-institutional collaborative venture to develop the next generation of open-access texts to improve postsecondary education at all levels of higher learning. The LibreTexts approach is highly collaborative where an Open Access textbook environment is under constant revision by students, faculty, and outside experts to supplant conventional paper-based books.

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Welcome to the Chemistry Library. This Living Library is a principal hub of the LibreTexts project, which is a multi-institutional collaborative venture to develop the next generation of open-access texts to improve postsecondary education at all levels of higher learning.

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Temperature has a direct effect on whether a substance exists as a solid, liquid or gas. Generally, increasing the temperature turns solids into liquids and liquids into gases; reducing it turns gases into liquids and liquids into solids.

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How atoms Back to Energy and molecules are affected by Heat:

Kinetic theory of matter: All matter is made up of atoms and molecules that are constantly moving.

When heat is added to a substance, the molecules and atoms vibrate faster. As atoms vibrate faster, the space between atoms increases. The motion and spacing of the particles determines the state of matter of the substance. The end result of increased molecular motion is that the object expands and takes up more space.

Solid at Different Temperatures

Mass of the object remains the same, however. Solids, liquids and gases all expand when heat is added. When heat leaves all substances, the molecules vibrate slower. The atoms can get closer which results in the matter contracting. Again, the mass is not changed.

Liquid at Different Temperatures

Solids: Sidewalks, bridges, telephone lines, railroad tracks, and other countless objects all expand on a hot summer day. They contract when they lose their heat.

In the picture to the left, some workers are trying to reconnect two rails that have separated due to the extreme cold. To fix the problem, the workers have lit an oil-soaked rope that lies next to the track. The heat of the fire will cause the tracks to expand so that they can be reconnected once again.

Liquids: Liquids expand when heated and they contract when cooled. Think about mercury in a thermometer! Ice however, expands when it freezes. As the water molecules lose heat, they vibrate less, and are able to form geometric patterns that take up more space. Remember that Density = Mass/Volume. As the volume of ice increases, the density of ice decreases and the ice floats.

Gases: Gases expand when heated and contract when cooled. For instance, a balloon will expand if it is left in a hot car. It will get smaller if it is put in the refrigerator.

Back to Energy
Common misconceptions: Students have difficulty understanding that molecules are constantly moving in all states of matter. Many students accept the fact that molecules are moving in liquid water because they can see water flow. However, these students have difficulty believing that the molecules in ice are also moving. Nevertheless, molecules are always moving, even in substances such as ice where no motion of the substance is visible.

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How atoms Back to Energy and molecules are affected by Heat: Kinetic theory of matter: All matter is made up of atoms and molecules that are constantly moving. When heat is added to a substance, the molecules and atoms vibrate faster. As atoms vibrate faster, the space between atoms increases.

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Mass of the object remains the same. Solids, Liquids and Gases all expand when heat is added. When heat leaves all substances, the molecules vibrate more slowly. The atoms can get closer which results in the matter contracting. Again the mass is not changed.

An increase in temperature means that some interparticular bonds are broken. Thus solids can melt to form liquids and eventually liquids will evaporate to become gases. We can see this when ice --> water --> steam
The state of matter a substance is in depends on temperature and pressure. A higher temperature provides more energy to the molecules in a substance.

From low energy to high energy:

Solid --- Liquid --- Gas

So at higher temperatures, matter will be at higher states on the above scale.

Yes. Water is a good example. When it is cold enough, water is a solid. Above 0°C, it is a liquid. Above 100°C, it is a vapour.

For solids, higher or lower temperatures cause almost every solid to either get larger (expand) or get smaller (shrink) Metallurgists have created metal alloys which change size by only minuscule or zero amounts. The steel in measuring tapes are made of a steel alloy called 'Invar'. So that they do not change their length when in below freezing, or used in the tropics. On hot days and on very cold days you will hear the noise as sheets of corrugated steel roofing, expand or contract and slide over each other where they lap. If solids are made very very hot they turn to a liquid. When stel is made it come out of the Smelter as a liquid and cools to a solid. While still red hot, it can be stretched to make steel bars any shape we require. For Liquids the same thing is true but to very much lesser degree. The main change that takes place in liquids as they are heated, is that they turn into a gas. Water turns to steam. When liquids are cooled they can freeze to become a solid. Water turns to ice. ALSO, if a gases such as oxygen or coal gas, are compressed to a very high pressure, they become liquid and occupy much less space. In Australia we obtain gas from the ground and compress it until it occupies very very much less space, and sell it in steel containers to use at BBQ's. When it has the pressure released it turns back to a gas and at the same time, it gets very very cold. All 'matter' is either a solid, or a liquid, or a gas and can be transformed from one form to the other

Temperature change is what normally causes the state of matter to be altered from a solid to a liquid, to a gas.

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How does temperature affect the states of matter? - Answers

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Mass of the object remains the same. Solids, Liquids and Gases all expand when heat is added. When heat leaves all substances, the molecules vibrate more slowly. The atoms can get closer which results in the matter contracting. Again the mass is not changed.An increase in temperature means that some interparticular bonds are broken.

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Transfer of heat to water kettle, 13 December 2010. GNU Free Documentation License, Version 1.2 via Wikipedia Commons

Purpose

To determine the effect of temperature on the motion of particles.

Context

One of the most important concepts for students to understand is that temperature affects the motion of molecules. As air is warmed, the energy from the heat causes the molecules of air to move faster and farther apart. Some students may have difficulty with this concept because they lack an appreciation of the very small size of particles or may attribute macroscopic properties to particles. Students might also believe that there must be something in the space between particles. Finally, students may have difficulty in appreciating the intrinsic motion of particles in solids, liquids, and gases; and have problems in conceptualizing forces between particles ( Benchmarks for Science Literacy, p.336.) In order to clarify student thinking about molecules and their relationship to temperature, instruction has to make the molecular world understandable to students.

The primary purpose of these activities is to introduce the students to the concept that temperature causes molecules and atoms to move faster and farther apart, which in turn causes the change from solid to liquid, and liquid to gas. Students need to come to this activity with the knowledge that some solids turn into liquids when heated. They also need to understand the observable differences between a solid and a liquid.

In "The Balloon and the Bottle," students experience the effects of increased temperature on air inside a balloon. As the air contained inside the balloon begins to warm, the molecules begin to strike the sides of the balloon harder and more often. This increases the air pressure and causes the balloon to expand. This activity also provides an opportunity to reinforce concepts related to the conservation of matter. According to research, many students in 6th and 7th grade still appear to think of weight simply as "felt weight" - something whose weight they can't feel is considered to have no weight at all. Measuring the weight of the bottle, balloon, and water at room temperature, after heating and after cooling, may help students dispel this misconception. If the balloon is not broken, the weight should stay the same. Research also states that many students can understand qualitatively that matter is conserved in transforming from solid to liquid. They also start to understand that matter is quantitatively conserved in transforming from solid or liquid to gas - if the gas is visible.( Benchmarks for Science Literacy, p.336.)

Motivation

Before you start the activity, students need to understand the difference between particles in a gas, liquid, and a solid. Have students look at the Gases, Liquids, and Solids page on the Purdue University Chemistry Department website. Here they will see how the characteristics of solids, liquids, and gases can be explained by particle motion.

Discuss what happens at both the observable and molecular level in these scenarios:

Water is placed in the freezer.

Ice melts.

A puddle evaporates.

Use the following demonstration to begin a discussion of the effect of temperature on particle movement. Blow up a balloon, and then aim a hair dryer on low setting at the balloon, and watch it rise.

Ask students:

What happens when I blow hot air on the balloon? Why?

What is happening to the air inside the balloon?

What do you think would happen if the balloon was placed in a cold car?

What would happen to the balloon as the temperature increases in the car? Why?

Ask the students to think about what might happen to a balloon in a bottle when it is heated.

Development

The Balloon and the Bottle
Give each student a copy of the Balloon and the Bottle student sheet, which includes questions and procedures.

Briefly review the procedure with students:

1. Pour about 15 ml. (1 tbsp) of water into an empty glass bottle/flask.

2. Weigh the bottle, water, and balloon using the balance. Record the weight on the data table.

3. Stretch the open balloon over the top of the bottle.

4. Heat the bottle until the water boils vigorously. Write down your observations of the water and the balloon on the data table.

5. Using an oven mitt, place the bottle with balloon on the balance. Record the weight on the data table.

6. Allow the bottle to cool. Write down observations of the balloon and the bottle.

7. Weigh the bottle and the balloon. Record information on the data table.

After students understand the procedure, ask them to make these predictions:

Will the weight change when the flask/bottle, water, and balloon are heated/cooled?

What do you think will happen to the balloon when the bottle is heated/cooled?

What is going to happen to the water when it is heated/cooled?

After students have completed the activity, ask them to record their answers to these questions on the student worksheet:

1. Compare your observations to your predictions.
A. Were your predictions correct?
B. Did anything surprise you during the experiment? If so, describe it.

2. What do you think caused the balloon to expand? What's going on outside the balloon that's causing this to happen?

3. Why do you think the balloon was sucked into the bottle? What's going on outside the balloon that's causing this to happen?

4. What did you observe inside the bottle as it cooled?

5. What's happening to particles inside the balloon? Are they moving? Were they moving?

6. How did this experiment demonstrate water changing from liquid to gas?

7. What would have happened if the bottle were placed in the freezer?

Assessment

In this assessment activity, students will illustrate in a cartoon scene the idea of how temperature affects the motion of molecules. Students should present their cartoon to the class and explain how it relates to the idea of temperature affecting the motion of molecules and states of matter.

Students should be assessed on how well their cartoons convey the following scientific ideas:

How heating and cooling affects the movement of particles.

How states of matter may change with heating and cooling.

Give the students these instructions:
You are a cartoonist. Your task is to create a cartoon scenario illustrating the effect of temperature on the movement of molecules in a solid, liquid, or a gas. You will use your cartoon to teach your classmates about the movement of molecules in the different states of matter and how an increase or decrease in temperature affects them.

Extensions

Go to Full of Hot Air! on the Science for Kids website. This activity allows the students to find out what happens when you heat a gas and cool it down. Have them compare the results of this activity to those of "Balloon in a Bottle."

Students could use the Web to find out other experiments that could be used to illustrate the effect of temperature. They could also find out about real life illustrations of how temperature affects everything. This would be a good opportunity to help students learn how to do a guided Web search at home or in school.

Kinetic Cards
The purpose of this activity is to allow students the opportunity to review new concepts and terminology related to states of matter. This would be a great way for students to review for tests.

Have students:

1. Generate words, phrases, or drawings that come to mind when they think of: States of Matter and Temperature

2. Work in small groups to share ideas and group them into categories.

3. Observe and analyze the work of other groups. One student stays behind at the table to answer questions and to note which cards are clear to the other students and which ones need further clarification..

4. Discuss what they observed and to revise or add new ideas/categories based on class feedback.

5. Create a class set of the cards. Students can keep their cards in an index box for further study.

Send us feedback about this Lesson >

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Transfer of heat to water kettle, 13 December 2010. GNU Free Documentation License, Version 1.2 via Wikipedia Commons To determine the effect of temperature on the motion of particles. One of the most important concepts for students to understand is that temperature affects the motion of molecules.

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Chemical Reactions That Cause Color Change

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Matter can exist in a solid, liquid or gaseous state, and the state a substance is in can be largely determined by its temperature. When a certain temperature threshold unique to each substance in the universe is crossed, a phase change will result, changing the state of the matter. Under conditions of constant pressure temperature is the primary determinant of a substance's phase. The differential in temperatures and the phases of different kinds of matter allows for the operation of heat engines and refrigerators.

TL;DR (Too Long; Didn't Read)

Temperature has a direct effect on whether a substance exists as a solid, liquid or gas. Generally, increasing the temperature turns solids into liquids and liquids into gases; reducing it turns gases into liquids and liquids into solids.

At low temperatures, molecular motion decreases and substances have less internal energy. Atoms will settle into low energy states relative to one another and move very little, which is characteristic of solid matter. As temperatures increase, additional heat energy is applied to the constituent parts of a solid, which causes additional molecular motion. Molecules begin to push against one another and the overall volume of a substance increases. At this point, the matter has entered the liquid state. A gaseous state exists when molecules have absorbed so much heat energy due to increased temperatures that they are free to move around one another at high speeds.

The point at which matter subjected to a particular temperature under conditions of constant pressure begins to change its phase is called the phase change threshold. At this temperature, every bit of the substance exposed to the heat will change its state. A shift from to a solid to a liquid occurs at the melting point, and the transition from a liquid to a gas takes place at the boiling point. Conversely, the moment of change from a gas to a liquid is the condensation point and the shift from a liquid to a solid takes place at the freezing point.

A substance may undergo phase change from a solid to a gas or from a gas to a solid if the temperature it is exposed to is changed very quickly. If the temperature around a solid is raised very quickly, it can sublimate, or phase change from a solid to a gas without existing as a liquid. In the opposite direction, a gas that is suddenly supercooled can undergo complete deposition.

If pressure is constant, the state of a substance will depend entirely on the temperature it is exposed to. For this reason, ice melts if taken out of a freezer and water boils out of a pot if left at too high a temperature for too long. Temperature is merely a measurement of the amount of heat energy present in the surroundings. When a substance is placed in surroundings of a different temperature, heat is exchanged between the substance and the surroundings, causing both to achieve an equilibrium temperature. So when an ice cube is exposed to heat, its water molecules absorb heat energy from the surrounding atmosphere and begin to move more energetically, causing the water ice to melt into liquid water.

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What Is the Effect of Temperature on States of Matter?

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Matter can exist in a solid, liquid or gaseous state, and the state a substance is in can be largely determined by its temperature. When a certain temperature threshold unique to each substance in the universe is crossed, a phase change will result, changing the state of the matter.

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Temperature is a measurement of the average kinetic energy of the molecules within a substance and can be measured using three different scales: Celsius, Fahrenheit and Kelvin. Regardless of the scale used, temperature exhibits its effect on matter due to its relationship with kinetic energy. Kinetic energy is the energy of motion and can be measured as the movement of molecules within an object. Examining the impact of different temperatures on kinetic energy identifies its effects on the various states of matter.

A solid is composed of molecules that are tightly packed together, thereby giving the object a rigid structure that is resistant to change. As temperature rises, the kinetic energy of the molecules within the solid begin to vibrate, which decreases the attraction of these molecules. There is a temperature threshold, referred to as the melting point, at which the vibration becomes sufficient enough to cause the solid to change to liquid. The melting point, in turn, also identifies the temperature at which the liquid will change back to the solid, so it is also the freezing point.

In a liquid, molecules are not as tightly compressed as in a solid, and they can move around. This gives liquid the important property of being able to take the shape of the container in which it is held. As the temperature -- and thus the kinetic energy -- of a liquid increases, the molecules begin to vibrate more rapidly. They then reach a threshold at which their energy becomes so great that the molecules escape into the atmosphere, and the liquid becomes a gas. This temperature threshold is called the boiling point if the change is from liquid to gas as the temperature increases. If the change is from gas to liquid as the temperature falls below it, it is the condensation point.

Gases have the highest kinetic energy of any state of matter and thus occur at the highest temperatures. Increasing the temperature of a gas in an open system will not further change the state of matter because the gas molecules will only become infinitely further apart. In a closed system, however, increasing the temperature of gases will result in an increase in pressure due to the molecules moving faster and the increased frequency of the molecules hitting the sides of the container.

Pressure is also a factor when examining the effects of temperature on the various states of matter. According to Boyle's Law, temperature and pressure are directly related, meaning that an increase in temperature results in a corresponding increase in pressure. This is again caused by the increase in kinetic energy associated with increasing temperature. At sufficiently low pressures and temperatures, solid matter may bypass the liquid phase and be converted directly from a solid to a gas through a process called sublimation.

About the Author

Matt Perdue is a medical student at an allopathic U.S. medical school. Beginning in 2010, he began writing science-related articles for eHow. He was also authored a paper for a medical journal exploring current recommendations for bone scans to diagnose osteoporosis.

Photo Credits

showcake/iStock/Getty Images

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How Does Temperature Affect the State of Matter?

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Temperature is a measurement of the average kinetic energy of the molecules within a substance and can be measured using three different scales: Celsius, Fahrenheit and Kelvin. Regardless of the scale used, temperature exhibits its effect on matter due to its relationship with kinetic energy. Kinetic energy is the ...

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Change in State of Matter - Effect of Temperature - Experiment

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Copyright © 2020 Multiply Media, LLC. All Rights Reserved. The material on this site can not be reproduced, distributed, transmitted, cached or otherwise used, except with prior written permission of Multiply.

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How heat energy affects the motion of particles? - Answers

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When heat is added to particles. The particles start to get heated which forces them to move at a greater speed then before, when you add heat to the particles they speed up and move faster. If you make particles colder then they will move at a slower speed.

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Change in State of Matter - Effect of Temperature - Experiment

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Changes of State | Matter |  Physics | FuseSchool

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7.3 Lesson Bolts part 3 change the substance to oil

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By temperature change while changing different aspects of a substance.

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During melting, energy goes exclusively to changing the phase of a ... The particles still slide over each other because they are in the liquid phase.

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All properties of matter are either physical or chemical properties and physical ... such as mass and volume, depend on the amount of matter being measured. Intensive properties, such as density and color, do not depend on the amount of the ... when water freezes, it's still water (H2O)—it's just in a different physical state.

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Matter: Definition & the Five States of Matter

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The four fundamental states of matter are solid, liquid, gas and plasma, but there others, such as Bose-Einstein condensates and time crystals, that are man-made.

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The Kinetic Molecular Theory of Matter

The kinetic molecular theory of matter explains how matter can change among the phases of solid, liquid, and gas.

Learning Objectives

Describe the kinetic molecular theory of matter.

Key Takeaways

Key Points

All particles have energy, and the energy varies depending on the temperature the sample of matter is in, which determines if the substance is a solid, liquid, or gas. Solid particles have the least amount of energy, and gas particles have the greatest amount of energy.

The temperature of a substance is a measure of the average kinetic energy of the particles. A change in phase may occur when the energy of the particles is changed.

There are spaces between particles of matter. The average amount of empty space between molecules gets progressively larger as a sample of matter moves from the solid to the liquid and gas phases.

Key Terms

kinetic molecular theory: Theory of treating samples of matter as a large number of small particles (atoms or molecules), all of which are in constant, random motion

kinetic: Of or relating to motion.

lattice: A regular spacing or arrangement of atoms/molecules within a crystal.

phase: A component in a material system that is distinguished by chemical composition and/or physical state. Matter can exist in the solid, liquid, and gaseous phases.

The Kinetic Theory: A Microscopic Description of Matter

The kinetic molecular theory of matter offers a description of the microscopic properties of atoms (or molecules) and their interactions, leading to observable macroscopic properties (such as pressure, volume, temperature). An application of the theory is that it helps to explain why matter exists in different phases (solid, liquid, and gas) and how matter can change from one phase to the next.

The kinetic molecular theory of matter states that:

Matter is made up of particles that are constantly moving.

All particles have energy, but the energy varies depending on the temperature the sample of matter is in. This in turn determines whether the substance exists in the solid, liquid, or gaseous state. Molecules in the solid phase have the least amount of energy, while gas particles have the greatest amount of energy.

The temperature of a substance is a measure of the average kinetic energy of the particles.

A change in phase may occur when the energy of the particles is changed.

There are spaces between particles of matter. The average amount of empty space between molecules gets progressively larger as a sample of matter moves from the solid to the liquid and gas phases.

There are attractive forces between atoms/molecules, and these become stronger as the particles move closer together. These attractive forces are called intermolecular forces.

Interactive: Intermolecular Attractions and States of Matter: Explore how states of matter are related to the strength of intermolecular attractions.

Example: Water

Let's take water as an example. We find that in its solid phase (ice), the water molecules have very little energy and cannot move away from each other. The molecules are held closely together in a regular pattern called a lattice. If the ice is heated, the energy of the molecules increases. This means that some of the water molecules are able to overcome the intermolecular forces that are holding them close together, and the molecules move further apart, forming liquid water. This is why liquid water is able to flow: the molecules have greater freedom to move than they had in the solid lattice. If the molecules are heated further, the liquid water will become water vapor, which is a gas. Gas particles have more energy and are on average at distances from each other which are much larger than the size of the atoms/molecules themselves. The attractive forces between the particles are very weak given the large distances between them.

Diffusion

The kinetic theory of matter is also illustrated by the process of diffusion. Diffusion is the movement of particles from a high concentration to a low concentration. It can be seen as a spreading-out of particles resulting in their even distribution. Placing a drop of food coloring in water provides a visual representation of this process - the color slowly spreads out through the water. If matter were not made of particles, then we would simply see a clump of color, since there would be no smaller units that could move about and mix in with the water.

Interactive: Diffusion of a Drop: Click in the model to add a drop of dye. Watch how the molecules move through the water. Trace an individual molecule to see how it moves through the liquid.

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The kinetic molecular theory of matter explains how matter can change among the phases of solid, liquid, and gas. Describe the kinetic molecular theory of matter. Key Points All particles have energy, and the energy varies depending on the temperature the sample of matter is in, which determines if the substance is a solid, liquid, or gas.

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Matter is any substance that has mass and takes up space; this includes atoms and anything made up of these, but not other energy phenomena or waves such as light or sound. While this simple definition is easily applied, the way people view matter is often broken down into two characteristic length scales: the macroscopic and the microscopic.

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You are SCIcentre / Self Study Resources / Particle Theory - Introduction

Topics covered
Melting Evaporating Boiling
Changes of state

The kinetic theory of matter can be used to explain how solids, liquids and gases are interchangeable as a result of increase or decrease in heat energy. When an object is heated the motion of the particles increases as the particles become more energetic. If it is cooled the motion of the particles decreases as they lose energy.

Melting

In a solid the strong attractions between the particles hold them tightly packed together. Even though they are vibrating this is not enough to disrupt the structure. When a solid is heated the particles gain energy and start to vibrate faster and faster. Initially the structure is gradually weakened which has the effect of expanding the solid. Further heating provides more energy until the particles start to break free of the structure. Although the particles are still loosely connected they are able to move around. At this point the solid is melting to form a liquid. The particles in the liquid are the same as in the solid but they have more energy. To melt a solid energy is required to overcome the attractions between the particles and allow them to pull them apart. The energy is provided when the solid is heated up. The temperature at which something melts is called its "melting point" or melting temperature. At room temperature a material is a solid, liquid or gas depending on its melting temperature. Anything with a melting temperature higher than about 20oC is likely to be a solid under normal conditions. Materials have widely differing melting temperatures e.g. mercury -39oC, ice 0oC, salt 1081oC, aluminium 660oC and steel 1535oC. Everyday materials such as ice, butter and wax have different melting temperatures and can be used as examples with children.
Ice is probably the melting substance most children are familiar with. It can be problematic when trying to develop an understanding of melting as it does often appear to them to melt without any source of heat. Ice melts at room temperature because the surrounding air is warmer than the ice and at a temperature above the melting temperature. The heat energy required to melt the ice comes from the surrounding air which will consequently become a little cooler.
Not all solids melt when they are heated. Some may undergo chemical changes as a result of heating. For example paper burns rather than melts.

Evaporating

Within a liquid some particles have more energy than other. These "more energetic particles" may have sufficient energy to escape from the surface of the liquid as gas or vapour. This process is called evaporation and the result of evaporation is commonly observed when puddles or clothes dry. Evaporation takes place at room temperature which is often well below the boiling point of the liquid. Evaporation happens from the surface of the liquid. As the temperature increases the rate of evaporation increases. Evaporation is also assisted by windy conditions which help to remove the vapour particles from the liquid so that more escape.
Evaporation is a complex idea for children for a number of reasons. The process involves the apparent disappearance of a liquid which makes the process difficult for them to understand. It is not easy to see the water particles in the air. Also, evaporation occurs in a number of quite differing situations - such as from a puddle or bowl of water where the amount of liquid obviously changes, to situations where the liquid is less obvious - such as clothes drying or even those where there is no obvious liquid at all to start with - such as bread drying out. A further complication is that evaporation may be of a solvent from a solution e.g. water evaporating from salt water to leave salt. These situations are quite different yet all involve evaporation.
Evaporation may also involve liquids other than water e.g. perfume, petrol, air fresheners. The particle model can be used to explain how it is possible to detect smells some distance away from the source.
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Boiling

If a liquid is heated the particles are given more energy and move faster and faster expanding the liquid. The most energetic particles at the surface escape from the surface of the liquid as a vapour as it gets warmer. Liquids evaporate faster as they heat up and more particles have enough energy to break away. The particles need energy to overcome the attractions between them. As the liquid gets warmer more particles have sufficient energy to escape from the liquid. Eventually even particles in the middle of the liquid form bubbles of gas in the liquid. At this point the liquid is boiling and turning to gas. The particles in the gas are the same as they were in the liquid they just have more energy. At normal atmospheric pressure all materials have a specific temperature at which boiling occurs. This is called the "boiling point" or boiling temperature. As with the melting point the boiling point of materials vary widely e.g. nitrogen -210oC, alcohol 78oC, aluminium 459oC.
Any material with a boiling temperature below 20oC is likely to be a gas at room temperature. When liquids boil the particles must have sufficient energy to break away from the liquid and to diffuse through the surrounding air particles. As these particles cool down and lose energy they will condense and turn back to liquid. When steam is formed by water boiling at 100oC the particles quickly condense as the surrounding air temperature is likely to be much less that 100oC so the particles cool rapidly. In fact the "steam" coming out of a boiling kettle can only be seen because some of the gas particles have condensed to form small droplets of water.
When a gas turns to a liquid (condenses) or a liquid turns to a solid (solidifies) the particles lose energy to the surroundings.

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Website maintainer: R. Jones Updated: November 13, 2000

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You are SCIcentre / Self Study Resources / Particle Theory - Introduction Melting Evaporating Boiling The kinetic theory of matter can be used to explain how solids, liquids and gases are interchangeable as a result of increase or decrease in heat energy.

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Most of us use the word 'heat' to mean something that feels warm, but science defines heat as the flow of energy from a warm object to a cooler object.

Actually, heat energy is all around us - in volcanoes, in icebergs and in your body. All matter contains heat energy.

Heat energy is the result of the movement of tiny particles called atoms, molecules or ions in solids, liquids and gases. Heat energy can be transferred from one object to another. The transfer or flow due to the difference in temperature between the two objects is called heat.

For example, an ice cube has heat energy and so does a glass of lemonade. If you put the ice in the lemonade, the lemonade (which is warmer) will transfer some of its heat energy to the ice. In other words, it will heat up the ice. Eventually, the ice will melt and the lemonade and water from the ice will be the same temperature. This is known as reaching a state of thermal equilibrium.

Moving particles

Matter is all around you. It is everything in the universe - anything that has both mass and volume and takes up space is matter. Matter exists in different physical forms - solids, liquids and gases.

All matter is made of tiny particles called atoms, molecules and ions. These tiny particles are always in motion - either bumping into each other or vibrating back and forth. It is the motion of particles that creates a form of energy called heat (or thermal) energy that is present in all matter.

The particles in solids are tightly packed and can only vibrate. The particles in liquids also vibrate but are able to move around by rolling over each other and sliding around. In gases, the particles move freely with rapid, random motion.

Transferring heat energy - particles in collision

At higher temperatures, particles have more energy. Some of this energy can be transmitted to other particles that are at a lower temperature. For example, in the gas state, when a fast moving particle collides with a slower moving particle, it transfers some of its energy to the slower moving particle, increasing the speed of that particle.

With billions of moving particles colliding into each other, an area of high energy will slowly transfer across the material until thermal equilibrium is reached (the temperature is the same across the material).

Changing states by heat transfer

Faster moving particles 'excite' nearby particles. If heated sufficiently, the movement of particles in a solid increases and overcomes the bonds that hold the particles together. The substance changes its state from a solid to a liquid (melting). If the movement of the particles increases further in the liquid, then a stage is reached where the substance changes into a gas (evaporation).

Three ways of transferring heat energy

All heat energy, including heat generated by fire, is transferred in different ways:

Convection transfers heat energy through gases and liquids. As air is heated, the particles gain heat energy allowing them to move faster and further apart, carrying the heat energy with them. Warm air is less dense than cold air and will rise. Cooler air moves in below to replace the air that has risen. It heats up, rises, and is again replaced by cooler air, creating a circular flow called a convection current. These currents circle and heat the room.

Conduction transfers heat energy in solids. The moving particles of a warm soild material can increase the heat energy of the particles in a cooler solid material by transferring it directly from one particle to the next. Since particles are closer together, solids conduct heat better than liquids or gases.

Radiation is a method of heat transfer that does not require particles to carry the heat energy. Instead, heat is transferred in infrared waves (part of the electromagnetic spectrum). Heat waves radiate out from hot objects in all directions, travelling at the speed of light, until they hit another object. When this happens, the heat energy carried by the waves can be either absorbed or reflected.

Fire illustrates the three different methods of heat transfer. For example, the firebox will heat up due to convection. The air above the fire will be warm due to convection. You can warm your hands near to the flames due to radiant heat transfer.

An effect of heat - expansion

When gases, liquids and solids are heated, they expand. As they cool, they contract or get smaller. The expansion of the gases and liquids is because the particles are moving around very fast when they are heated and are able to move further apart so they take up more room. If the gas or liquid is heated in a closed container, the particles collide with the sides of the container, and this causes pressure. The greater the number of collisions, the greater the pressure.

Sometimes when a house is on fire, the windows will explode outwards. This is because the air in the house has been heated and the excited molecules are moving at high speed around the room. They are pushing against the walls, ceiling, floor and windows. Because the windows are the weakest part of the house structure, they break and burst open, releasing the increased pressure.

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Most of us use the word 'heat' to mean something that feels warm, but science defines heat as the flow of energy from a warm object to a cooler object. Actually, heat energy is all around us - in volcanoes, in icebergs and in your body. All matter contains heat energy.

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Every student should post a (1) picture, (2) video, and (3) website that may be used as a resource to answer the question above.

After you post the resources above, make another post that answers the question above.

Finally, be sure to put your name and the kind of post in the title (i.e. Maffett's Picture, Maffett's Video, Maffett's Website, Maffett's Answer)

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We are Citizens of Change

World-class teaching and research-inspired learning in one of the UK's most diverse cities. Are you ready to make a difference? Then let's start.

What do you want to change?

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We are Citizens of Change World-class teaching and research-inspired learning in one of the UK's most diverse cities. Are you ready to make a difference? Then let's start. What do you want to change?

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Chemists make a distinction between two different types of changes ... Because the ending materials are the same as the beginning materials, the properties (such as ... properties of the material change, but the identity of the matter does not. ... is the same: 11.19% hydrogen and 88.81% oxygen by mass.

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If heat is removed from a substance, such as in freezing and condensation, then the process is exothermic. In this instance, heat is decreasing the speed of the molecules causing them move slower (examples: liquid to solid; gas to liquid). These changes release heat to the surroundings.