While essential for human life, oxygen also produces cellular abnormalities and other problems.

The atomic oxygen produced quickly reacts with another oxygen molecule to reform ozone:

In the presence of oxygen, carbon monoxide burns with a blue flame, producing carbon dioxide.

Hence, oxygen produced by this chemical reaction somehow 'absorbed' the energy released by the reaction and became excited.

The oxygen produced by radiolysis forms tenuous atmospheres around rings and icy moons.

Methane and oxygen produced an explosive mixture of gases.

During respiration oxygen and glucose produce carbon dioxide and water.

In plants, cyanobacteria and algae, oxygenic photosynthesis splits water, with oxygen produced as a waste product.

Because the oxygen produced migrates away, the reaction only goes forwards.

The oxygen they produce benefits the fish, and they also provide a source of food and shelter.