Background Information
Oxygen is a diatomic molecule, meaning that two atoms of oxygen combine to form the element in its natural state. Oxygen is extremely reactive and reacts with most other elements to form oxides.

Oxygen’s existence has been predicted and experimented with for thousands of years. It is always been clear that there is a reactive substance in the atmosphere that enables a lot of chemical reactions to take place and that also there is a substance that enables us to breath.

Oxygen was first discovered by Swedish pharmacist Carl Wilhelm Scheele. He had produced oxygen gas by heating mercuric oxide and various nitrates by about 1772. Scheele called the gas “fire air” because it was the only known supporter of combustion.

How is it used in everyday life?

Oxygen’s major modern application is to do with respiration and life support. It is used to help people breathe when they are ill with pulmonary (lung) diseases. It is also used in space for life support for astronauts who need to breathe in an environment that is a vacuum and doesn’t facilitate oxygen.

Oxygen is found in virtually every chemical compound on the planet as virtually all reactions use it as a catalyst (something that helps the reaction move forward).