AP BIOLOGY

Detailed explanation-1: -The atmosphere is the layer of gases that surround the Earth. In comparison to the size of the Earth, it is a thin layer, composed primarily of nitrogen and oxygen with small amounts of carbon dioxide and other gases.

Detailed explanation-2: -The four spheres are the geosphere (all the rock on Earth), hydrosphere (all the water on Earth), atmosphere (all the gases surrounding Earth), and biosphere (all the living things on Earth).

Detailed explanation-3: -Troposphere. The troposphere is the lowest and densest layer of the atmosphere and according to NIWA, approximately 75% of all the air in the atmosphere is found in this layer.

Detailed explanation-4: -It’s a mixture of different gases. The air in Earth’s atmosphere is made up of approximately 78 percent nitrogen and 21 percent oxygen. Air also has small amounts of other gases, too, such as carbon dioxide, neon, and hydrogen.

Detailed explanation-5: -Atmosphere: It is the layer of gases that surrounds the earth. It is composed of 78% nitrogen, 21% oxygen, 0.9% argon, and 0.1% other gases. It has 5 layers-troposphere, stratosphere, mesosphere, thermosphere, and exosphere.