Layers of the Atmosphere
Middle school students learned about the layers of the atmosphere and modeled Earth’s atmosphere with various liquids of different densities. Students observed how they layered within a beaker and related that to how the different densities of air within the Earth’s atmosphere also creates layers. Students even produced their own hypothesis and predicted that even if they mixed all the layers in their beaker together, they would still separate out to their distinct layers.
The purpose of this lab is to observe and explore the scientific principles which create the distinct layers of the Earth’s atmosphere. The atmosphere is separated into distinct layers due to the density of the gas molecules in the atmosphere. Heavier molecules (oxygen and nitrogen) “sink” towards the bottom of the atmosphere and lighter molecules (argon, neon, methane, and hydrogen) rise to the top. Since the majority of the atmosphere is made up of nitrogen and oxygen, these molecules form a very densely (tightly packed) layer of air at the bottom of the atmosphere, known as the troposphere. The amount of nitrogen, oxygen, and carbon dioxide gradually decreases while approaching the thermosphere, where the air is primarily oxygen, helium, and hydrogen. These gasses gradually spread out (air becomes less dense) as the atmosphere approaches and blends with outer space in the layer known as the exosphere.
Interesting work, middle school!