Oxygen is the simplest group VIA element and is, under normal atmospheric conditions, usually found as a colorless, odorless and tasteless gas. Oxygen has an atomic number of 8 and an atomic mass of 16.0 amu. The liquid and solid forms, which are strongly paramagnetic, are a pale blue color. Oxygen has a boiling point of -297°F (-182.8°C) and a melting point of -368.7°F (-222.6°C).

Oxygen is the third most abundant element found in the Sun, after hydrogen and helium, and plays an important role in the carbon-nitrogen cycle. Oxygen composes 21% of Earth's atmosphere by volume and is vital to the existence of carbon-based life forms.

Although English chemist Joseph Priestley (1733-1804) is generally credited with the discovery of oxygen in 1774, many science historians contend that Swedish chemist Carl Scheele (1742-1786) probably discovered oxygen a few years prior to Priestly. French chemist...