The chemical symbol for nitrogen is N. This symbol is derived from the Latin word "nitrum," which refers to nitre, a compound containing nitrogen. Nitrogen is a colorless, odorless gas that makes up about 78% of the Earth's atmosphere, playing a crucial role in various biological processes, including the nitrogen cycle. It is also an essential component of amino acids, proteins, and nucleic acids, making it vital for all living organisms. Nitrogen is used in fertilizers, explosives, and various industrial applications, highlighting its importance beyond biological systems.