Observing Gases Air is made out of gases. A gas is a kind of matter. Where is the air in each picture? You can not see most gases.
-A gas is matter that does not have its ownshape.-It spreads out to fill its container.-It takes that shape of the container.
Heating and Cooling Matter Heating and cooling can change matter. You can see how matter changes by observing water. Stream in summer Stream in winter In summer, the water in this stream is warm. Being In winter, the water in the stream gets cold. When warm keeps the water liquid. the water gets cold enough, it changes into ice. Ice is solid waterIn spring, the water will get warm again. It will change back to a liquid.
What is steam? When water boils, it becomes a gas. This gas is called steam. When the water gets hot enough, it becomes steam. The steam goes into the air. As steam cools, it forms tiny drops of water that make a little cloud.
Put on your thinking caps! What is gas? What is steam? Think about how and why matter may change. What would happen if you blew air into a bag? Why? What changes water from liquid to a solid?