Why is air classified as matter

Read more about the contraction and expansion of gases in the teacher background section. Show the molecular model animation Comparing Solids, Liquids, and Gases.

Be sure students realize that the molecules shown are from three different substances all at room temperature. The solid is not melting to become a liquid and the liquid is not evaporating to become a gas. The model is not trying to show state changes but instead show three different substances which are solid, liquid, and gas at room temperature.

You could use the following example to help students appreciate how far apart the molecules of a gas are compared to the molecules in a liquid or solid:. Draw or project the illustration Solid, Liquid, and Gas. Have students use the projected illustration as a reference as they draw a model of solids, liquids, and gases on their activity sheet. Point out that the number of motion lines is the same for the solid, the liquid, and the gas.

This indicates that the different substances are at the same temperature. Have students write captions like those listed below to describe the molecules in solids, liquids, and gases. Imagine that you work at a party store during the summer.

You are going to ride home with the owner of the store whose car has been sitting in the hot sun all day long. The owner tells you that you can take home a big bunch of balloons, but advises you to not blow the balloons up all of the way. You may choose to show the animation Heating Molecules of a Gas if you would like to give students a hint.

The American Chemical Society is dedicated to improving lives through Chemistry. Skip Navigation. Lesson 1. Engage Discuss with students whether they think gas is matter. Ask students about gases: Are gases, like the gases in air, matter?

Students may have questions about whether or not gases are matter. They may also have only a very vague sense of what gases are at all.

After students reply, explain that the air around them is made up of some different gases—nitrogen, oxygen, carbon dioxide, water vapor, and very small amounts of some others. Tell students that gases are made of molecules but that the molecules are much further apart than the molecules in liquids or solids. Since the molecules of a gas have mass and take up space, gas is matter.

Do a demonstration to show that gas has mass. Materials for the demonstration Basketball, very deflated Balance that measures in grams Pump Can of compressed gas available at any office supply store Procedure Basketball Place the deflated ball on the balance to get the initial mass. Ask students if they think the ball will weigh more or less after you pump air into it. Pump as much air into the basketball as you can and then put it back on the balance.

Can of compressed gas Place a can of compressed gas on a scale and check its mass. Shoot gas out of the can for a few seconds and then place the can back on the scale. Expected results The basketball should weigh 2—4 grams more than when it was deflated. Show an animation of the molecules of a gas.

Give each student an activity sheet. Explore Have students do an activity to find out how heating and cooling affect gases. Question to investigate How does heating and cooling affect a gas? While holding the bottle, slowly push the bottom of the bottle down into the hot water. Ask students: What can you do to make the bubble go down? If students have trouble thinking of an answer, remind them that heating the gas increased the speed of the molecules, which made the bubble grow.

Students should suggest that they should cool the gas in the bottle. This can be done by putting the base of the bottle into cold water. If there is still a bubble on the bottle, slowly push the bottom of the bottle down into the cold water. If a bubble is not still on the bottle, make another bubble by dipping the opening into detergent and then pushing the bottom of the bottle into hot water again.

While holding the bottle, slowly push the bottom of the bottle down into the cold water. Expected Results When the bottle is placed in hot water, a bubble forms at the top of the bottle. Mixtures with a consistent composition throughout are called homogeneous mixtures or solutions.

Sugar dissolved in water is an example of a solution. A metal alloy, such as steel, is an example of a solid solution. Air, a mixture of mainly nitrogen and oxygen, is a gaseous solution. Show Answer. Another way to classify matter is to describe it as a solid, a liquid, or a gas, which was done in the examples of solutions. These three descriptions, each implying that the matter has certain physical properties, represent the three phases of matter.

A solid has a definite shape and a definite volume. Liquids ordinarily have a definite volume but not a definite shape; they take the shape of their containers. Gases have neither a definite shape nor a definite volume, and they expand to fill their containers.

We encounter matter in each phase every day; in fact, we regularly encounter water in all three phases: ice solid , water liquid , and steam gas. We know from our experience with water that substances can change from one phase to another if the conditions are right. Typically, varying the temperature of a substance and, less commonly, the pressure exerted on it can cause a phase change , a physical process in which a substance goes from one phase to another Figure 1.

Phase changes have particular names depending on what phases are involved, as summarized in Table 1. Figure 1. Explain the differences between the physical properties of matter and the chemical properties of matter. What is the difference between a heterogeneous mixture and a homogeneous mixture?

Give an example of each. Give at least two examples of a phase change and state the phases involved in each. Does each statement refer to a chemical property or a physical property? Define element. How does it differ from a compound? Define compound. How does it differ from an element? Identify each substance as an element, a compound, a heterogeneous mixture, or a solution.

Identify each material as an element, a compound, a heterogeneous mixture, or a solution. An element is a substance that cannot be broken down into chemically simpler components. Compounds can be broken down into simpler substances.

Privacy Policy. Skip to main content. Chapter 1: Chemistry, Matter, and Measurement. It's like diving into a pool and feeling the pressure increase as you go deeper into the water, except liquid water doesn't compress nearly as readily as gaseous air. While you can't see or taste the air, that is because as a gas, its particles are very far apart. When air is condensed into its liquid form, it becomes visible. It still doesn't have a flavor not that you could taste liquid air without getting frostbite.

Using human senses isn't a definitive test for whether something is matter or not. For example, you can see light, yet it's energy and not matter.

Unlike light, air has mass and takes up space. Actively scan device characteristics for identification. Use precise geolocation data. Select personalised content. Create a personalised content profile. Measure ad performance. Select basic ads. Create a personalised ads profile. Select personalised ads. Apply market research to generate audience insights. Measure content performance. Develop and improve products. List of Partners vendors.

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