AP BIOLOGY

Detailed explanation-1: -Earth’s atmosphere is composed of about 78% nitrogen, 21% oxygen, and one percent other gases. These gases are found in atmospheric layers (troposphere, stratosphere, mesosphere, thermosphere, and exosphere) defined by unique features such as temperature and pressure.

Detailed explanation-2: -Air is mostly gas 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-3: -Early oxygen bonded with iron to form a layer of rust, but eventually began to build up in Earth’s atmosphere. As carbon dioxide was broken down by cyanobacteria, more CO2 could be dissolved into the ocean. This gave rise to our modern atmosphere dominated by nitrogen and oxygen.

Detailed explanation-4: -By volume, the dry air in Earth’s atmosphere is about 78.08 percent nitrogen, 20.95 percent oxygen, and 0.93 percent argon. A brew of trace gases accounts for the other approximately 0.04 percent, including the greenhouse gases carbon dioxide, methane, nitrous oxide and ozone.

Detailed explanation-5: -Nitrogen is not stable as a part of a crystal lattice, so it is not incorporated into the solid Earth. This is one reason why nitrogen is so enriched in the atmosphere relative to oxygen.