The element with the atomic number 8 is oxygen. Oxygen is a vital chemical element essential for life, as it is necessary for cellular respiration in most living organisms. It exists as a diatomic molecule (O2) in the atmosphere, making up about 21% of the Earth's air. Oxygen is highly reactive and forms compounds with nearly all other elements, which is crucial for forming various minerals and organic structures. Beyond its biological importance, oxygen is utilized in diverse applications, including combustion processes, medical uses, and industrial manufacturing, underscoring its significance in multiple facets of science and technology.