Show high or low pressure of the air molecules by spacing the balls in a glass jar and by compressing them. For example, high pressure can be shown by pressing down on the balls, moving them closer together. Briefly describe each layer of the atmosphere. Point out that the atmosphere is separated into layers based on the temperature changes that occur from one layer to the next. As we go higher into the atmosphere, generally, the temperature drops and the air molecules get thinner.
Most weather occurs in the troposphere.
Next have students make their own models, or draw pictures to reinforce the concepts. Have the students paste styrofoam packing pieces onto large oaktag in an arrangement that represents the molecules in each of the four layers of the atmosphere. Next, discuss how several factors affect the amount of radiation that is absorbed by the earth at different places. Begin by relating information about how the rays from the sun heat the earth's surface. Next ask if students have noticed how the way sunlight hits the earth changes during the day.