a chemical element with symbol O and atomic number 8. Its name derives from the Greek roots ???? (oxys) ("acid", literally "sharp", referring to the sour taste of acids) and -????? (-g?nos) ("producer", literally "begetter"), because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition. At standard temperature and pressure, two atoms of the element bind to form dioxygen, a colorless, odorless, tasteless diatomic gas with the formula O 2. This substance is an important part of the atmosphere, and is necessary to sustain most terrestrial life

At -183.0DegreeC oxygen is a beautiful pale blue liquid, but at room temperature it is a colorless gas. It's only 21% of the atmosphere--the 21% we all need if we want to live more than a few minutes longer.