Chemical element with the chemical symbol O for the atom or O2 for the molecule and the atomic number 8. This shows that it has the valence number 2. Oxygene is very reactive and therefore involved in many chemical reactions. Small fractions of the elementary gas consist from ozone O3. Oxygene is the most frequent chemical element in the earth crust and takes a portion of 21% of the atmopshere.

Oxygene also is of major relevance in plasma processes used as a process gas particularly for plasma cleaning and for plasma activation of plastics.

Oxygene Plasma
Cleaning process in an oxygene plasma
Activation of a non polar plastic surface by an oxygene plasma.
Typical colour of an oxygene plasma