Introduction. What makes water so unique

We drink water in many beverages, bathe in it, wash and clean ourselves in it, eat it as ice and breathe it in as its vapour. It forms part of the air, most of the sea and a considerable amount of the polar regions. It covers approximately three-quarters of the Earth s surface. It falls as rain, mist, fog, snow, hail, frost and ice. Our bodies are over 90 % composed of it and all the chemical reactions of the body depend upon it. Without it we would die - too much of it and we will drown. 

Our bodies make it when they produce energy from oxidation of carbohydrates ready for us to use and live. The water vapour produced by this reaction is exhaled in breath. We make hundreds of litres of it in a year. 

Before we were born, we lived in a sac of it, without drowning, but we need special apparatus to breathe in it after we are born. Fish manage to extract enough air from it to breathe. 

Deserts do not have enough of it but monsoons have too much of it. British holiday makers hate it but Sahara dwellers long for it. Skiers love it, but motorway drivers hate it. 

It has a unique property of freezing at 0 °C and boiling at 100 °C. It is a very important solvent but not everything dissolves in it. Fortunately our skin does not dissolve in it. 

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