Oxygen is a reactive gas central to respiration, combustion, and much of the chemistry of Earth's crust.
Atomic number
8
Category
Reactive nonmetal
Period
2
Group
16
State
Gas
Fun facts about Oxygen
Diatomic oxygen makes up about one fifth of dry air.
Ozone is a three-atom allotrope that absorbs much ultraviolet radiation.
Many rocks contain oxygen bound in silicate minerals.
Common uses of Oxygen
Medical oxygen
Steelmaking
Oxy-fuel cutting and welding
Where Oxygen sits in the periodic table
Oxygen is classified as a reactive nonmetal in period 2 and group 16 of the periodic table. Under the conditions represented in this reference, its state is gas.
Quick chemistry revision
For quick revision, pair the symbol O with atomic number 8 and the listed atomic mass 15.999. The summary, facts, and uses above keep those element properties together in one reference.