Oxygen is a chemical element with the symbol "O" and atomic number 8. It is a colorless, odorless, and tasteless gas that makes up about 21% of the Earth's atmosphere by volume.
The main applications of oxygen in order of importance are: 1) melting, refining and manufacture of steel and other metals; 2) manufacture of chemicals by controlled oxidation; 3) rocket propulsion; 4) medical and biological life support; 5) mining, production and manufacture of stone and glass products.
The most abundant form of oxygen on Earth is dioxygen, which is its chemical name, whose formula is O2. This form of oxygen is also known as molecular oxygen and can be found in the atmosphere or dissolved in oceans. Two atoms of oxygen are chemically bonded to form the dioxygen molecule.
Oxygen is a chemical element with an atomic number of 8 (it has eight protons in its nucleus). Oxygen forms a chemical compound (O2) of two atoms which is a colorless gas at normal temperatures and pressures.