The term for the primary component of the atmosphere is "nitrogen." Nitrogen makes up about 78% of the Earth's atmosphere, making it the most abundant gas present. It is colorless, odorless, and plays a crucial role in various biological processes, including the nitrogen cycle, which is vital for plant growth. Despite its abundance, nitrogen is generally inert and does not readily react with other substances, which is essential for maintaining the stability of the atmosphere. It serves as an essential component of amino acids and nucleic acids, integral to life on Earth.