oxygen (elemental) [O]

Introduction

Also see molecular oxygen (O2) From the Greek oxy genes meaning acid forming. The name derived from an inaccurate belief of Lavoisier that oxygen was needed to form all acids. Discovery generally credited to English chemist Joseph Priestly in 1774.

Occurrence

• makes up about 21% of the atmosphere by volume
• found combined in water, in most rocks & minerals, & numerous organic compounds
• ozone (O3) is a reactive gas in the upper atmosphere & in smog

Characteristics

• colorless tasteless odorless gas
• pale blue as a liquid or solid
• capable of combining with all elements except the inert gases

Uses

• active in physiological processes
• essential for respiration
• involved in combustion processes

More general terms

• chemical element

More specific terms

• oxygen-15

Additional terms

• O2 (molecular oxygen)
• periodic table

Database

• PubChem: http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=977