Oxygen  [ Return towards  Air gases  ]

Oxygen is essential to many life forms: at the cellular level, it is used to “burn” glucose, which supplies energy to living organisms.

A part of the oxygen is also converted into ozone in the stratosphere, protecting the Earth from the Sun’s UV radiation. Without this protection, Sun rays would break down cellular DNA, causing sunburns and skin cancer.

Oxygen was discovered in 1774 by Joseph Priestley.

More about oxygen history

To produce oxygen, it is necessary to separate it from the other constituents of air, such as nitrogen (78%). Air turns to liquid at a very low temperature (around -190°C). Its components (nitrogen, oxygen, noble gases) are then separated through cryogenic distillation.

Another technique uses micro-porous materials that trap or “adsorb” nitrogen contained in air. Upon contact with these adsorbent materials, often zeolites, nitrogen is removed from air and oxygen can be recovered then.

More about oxygen production

At normal temperature and pressure, oxygen is a colorless, odorless, and tasteless gas. A highly reactive element, it can form compounds with almost all other elements by oxidizing them. The best-known example is combustion, which also happens to be one of its key applications. Organic compounds burn intensely upon contact with oxygen, and this is why oxygen-based combustion is heavily used in industry.

Oxygen is also the “gas of life”. It is vital to human respiration. Medical oxygen enables to help patients with respiratory failure or those suffering from COPD (Chronic Obstructive Pulmonary Disease).

Discover the various applications of oxygen

More about this gas: its physical-chemical properties