Water is vital to all life on earth, without it, nothing would ever survive. Even though over two thirds of our planet is covered with water, only 1% of this can be used for drinking, as the rest is either too salty or is frozen.
Water makes up around 70% of our body weight. A person can survive for up to four weeks without food but no longer than three days without water, as it is needed to perform many important functions
inside our bodies.
The chemical symbol for water is H2O. The H stands for hydrogen and the O is for oxygen. Each molecule of water contains two bits of hydrogen and one bit of oxygen, which is what the ‘2’ stands for. Water is the only substance that can be found in three different forms; liquid, gas and solid. Freezing water turns into a solid called ice, while boiling it changes it into a gas called water vapour.