Yetdespite the fact that it is so common, we are hardly aware of this vital element because oxygen istransparent, it has no colour, taste or smell. Indeed, oxygen is among the most reactive of all the elements. For example, nearly allthe rocks of the Earth are compounds containing oxygen.
Water is also a compound of oxygen along with hydrogen.
Oxygen is vital for life. When oxygen reacts with a fuel, the fuel is oxidised and becomes an oxide, sometimes turning into a solid, in other cases forming a gas such as carbon dioxide. The reaction of oxygen with fuels such as coal, oil and natural gas can also be harnessed to convertthe chemical energy in the fuel into movement energy. This is how we power many ofour machines. The carbohydrates in our food, for example, oxidise to release energy for our bodies.