At room temperature, oxygen is found in a gaseous state. The element is also typically found in a diatomic state, as O2. Oxygen is found as a gaseous state because it is an essential part of Earth's atmosphere, and is used as a gas by organisms throughout the planet.
Oxygen is an element with an atomic number of eight, a rounded atomic mass of 16 and the atomic symbol "O." It was first discovered in 1774 by two different scientists around the same time. The element has since been found to be the most abundant element in the world and roughly comprises 21 percent of the Earth's atmosphere.