The primary gas in the air we breathe is "nitrogen." Comprising about 78% of Earth's atmosphere, nitrogen is a colorless, odorless gas that plays a vital role in the environment. While nitrogen itself is not directly usable by most living organisms, it is an essential component of proteins, nucleic acids, and other biological molecules. The nitrogen cycle helps convert atmospheric nitrogen into forms that can be absorbed by plants, thus supporting life. Although oxygen is crucial for respiration, nitrogen is the most abundant gas in the air surrounding us.