Nitrogen

Discovered by: Attributed to the Scottish physician Daniel Rutherford in 1772, who called it noxious air.

What is it? At standard temperature and pressure, two atoms of the element bond to form N2, a colorless and odorless diatomic gas.

Why is it important? N2 forms about 78% of Earth's atmosphere, making it the most abundant uncombined element in air. Nitrogen occurs in all organisms, primarily in amino acids (and thus proteins), in the nucleic acids (DNA and RNA) and in the energy transfer molecule adenosine triphosphate.