# Overview of Section Resources

Section 1: Air Takes Up Space
Students begin their investigation of air by learning about solids, liquids, and gases. They learn that gases are made up of tiny particles that ﬂoat around. Then they do a number of short experiments to show that air takes up space. When they push on an air-ﬁlled balloon, they see that the balloon pushes back. When they try to force a bag into an air-ﬁlled jar, they see that the bag will not go in because the space is already occupied. A paper towel in an inverted cup remains dry even as the cup is lowered into a water bath because air in the cup keeps the water away from the towel. Finally, students blow bubbles under water and observe that air rises in water because air is less dense than water.
Section 2: Hot Air, Cold Air
Students conduct experiments to see that air expands when heated and contracts when cooled. They also observe that hot air rises in cooler air. By modeling the expansion and contraction of air particles, they see that warm air is less dense than cold air. They also learn the role of heat energy in the expansion and contraction of gases.
Section 3: Air Pushes on Things
Students observe how air pressure affects liquid in a barometer and how a barometer can be used to measure changes in air pressure. Students then observe how air pressure can hold water in a straw and in an inverted cup, and how differences in air pressure can push objects from one place to another.
Section 4: Using Air to Move Things
Students do a series of experiments to see how air can be used to move heavy objects, including books and even people. They observe how moving air can move objects, and how lighter objects are moved a greater distance than heavier objects by the same amount of force. Students go on to make jet-propelled balloons and observe how air rushing out of a balloon generates thrust. Finally, they experiment with their balloon setups to maximize travel distance.
Section 5: Parachutes and Airplanes
Students begin by making model parachutes and observing how they create air resistance that slows the rate at which objects fall. Then they demonstrate how fast-moving air exerts less pressure than slow-moving air. Lastly, students construct model airplanes and relate the shape of the airplanes to the characteristics of their ﬂight patterns. They see that some airplanes are designed to minimize air resistance while others are designed to maximize it.