Answer:
The atmosphere: is mostly made of nitrogen, protects the Earth from harmful radiation, and contains water vapor.
Step-by-step explanation:
The atmosphere can be defined as the gassy wrapping covering a planet, in this case, the Earth.
The Earth´s atmosphere is composed of water vapor, N₂ (78.08%), O₂ (20.95%), Ar (0.93%), CO₂ (~0.03%), and Oz (0.01%). There are also other gases in reduced concentrations. Water vapor might reach 4% of the atmosphere near the Earth's surface. Water vapor and ozone absorb infrared radiation and are important in defining the terrestrial clime and keeping the environmental conditions needed for life. They protect the Earth from harmful radiation.
The atmosphere is composed of different layers: troposphere, stratosphere, mesosphere, thermosphere, and exosphere. The troposphere is the most inferior layer, in contact with the Earth´s surface, composing almost 90% of the atmospheric mass.