Oxygen is a chemical element with symbol O and atomic number 8. It is a member of the chalcogen group on the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as well as with other compounds.

Atomic Weight:  15.999
Density:        1.429 g/l
Melting Point:  -218.3 °C
 Boiling Point: -182.9 °C