Give your class a colorful and tasty representation of the components of the mixture that we call air. Pop a few batches of popcorn in four different colors, one to represent each gas: nitrogen, oxygen, argon, and carbon dioxide. The unit that this instructional activity is part of contains lessons and additional resources that can be used with primary scientists; however, the concepts relating to different gases may be difficult for them to grasp. They would need to have some understanding of different elements and compounds to fully benefit from the demonstration.