Oxygen is a colorless and tasteless gas

It forms 21% of the atmosphere by volume and 23% by weight

It makes up one half of earth's crust and one fifth of the air we breath

It doesn't burn

It can also be a liquid and a solid


Oxygen is used to make different acids

Hot oxygen air is required to make iron and steel

It is also used to cut and melt metals

It is used in airplanes and cars

Some mining companies use it to destroy rocks


Oxygen was discovered in 1774

Before oxygen air was felt to be an element in its own right

It was prepared by workers before 1772 but they didn't recognize it as an element