Quick Facts:

Atomic Number: 8

Symbol: O

Melting Point: -218.79 degrees Celsius

Boiling Point: -182.95 degrees Celsius

State at Room Temp.: Gas

Atomic Weight: 16.00

Atomic Radius: 152 pm (Van der Waals)

Atomic Mass: 15.999

Group in Periodic Table: 16

Category: Non-metal

Isotopes: 9, 3 of which make up natural oxygen

Description: colorless, odorless, tasteless gas; pale blue and strongly paramagnetic liquid and solid forms


Oxygen is used for many things. Because it has 6 valence electrons, it reacts very easily to many other elements. Because of this, oxygen is in many different compounds, for example, water. Oxygen is also required by most living things on earth for breathing. Oxygen can also be used for an extremely hot flame for welding. Also, combined with liquid hydrogen, liquid oxygen makes very good rocket fuel.


Oxygen was discovered in 1774 in England and Sweden by Carl Scheele and Joseph Priestley. Before this, however, Leonardo da Vinci had suggested that there were at least two different gasses making up air. The popular belief at this time was that air was an element in its self. da Vinci also knew that one of those gasses supported fire and life. Although Joseph Priestley gets most of the credit for discovering oxygen, Carl Scheele also reported it in independent studies he made.
oxygen 1.jpg


Oxygen is very reactive, so it is used in many different materials. The most industrial use of oxygen, however, is oxygen enrichment for basic-oxygen steel making furnaces. Large quantities of oxygen are also used for making synthesis gas for methanol, ammonia, ethylene oxide, and oxy-acetylene welding. Hospitals and other medical centers also stock up on oxygen for patients with respiratory problems. Oxygen is also stocked up for space shuttles, air planes, and submarines. Liquid oxygen is used for rocket fuel when combined with liquid hydrogen.