Commonly referred to as H20, Aqua, is one of the most important elements to the human race, with the body made up of up to 78%.  The globe is covered by over 76% of water of which only 12% is drinkable.  It can exist in gas, liquid, ubiquitous and solid forms.  Water is the only common substance that found in these states naturally.   Water is colourless, odourless and tasteless. 

One of the attributes to water is that substances can be dissolved in water (such as minerals) bacteria can grow in water, fish can live in water.  Because of this attribute, water is very rarely pure.  For humans pure water is not ideal as we require mineral and salts to be present.

The water molecule is very small, measuring only 0.278 Nano metres (0.278 x10-9 m or .000278 x 10-6m or 0.000278 microns) 

A water molecule consists of two hydrogen and one oxygen atom weighing 18g/molecule. They are polar covalently bonded together forming a V-shaped molecule. Water molecules are typically symmetric.  Each molecule has a slightly more positive and slightly more negative side.  This is because the water molecules are polar covalently bonded, that is share electrons unequally.  Other non-water polar molecules can surround the water molecule.

One interesting fact about water is that unlike many substances, when water is at 4ºC or less, water stars to expand meaning that density is less in a frozen state.  When water is referred to as hard water, it often means that it contains higher than normal concentration of minerals.  Some of the minerals could be magnesium and calcium.

The water molecule is one of the smallest and lightest around.  The compound is simple, with common reactive elements, yet one of the most amazing substances known.  Behind Hydrogen H2 Water H2O is the most common molecule.

When in a liquid form, the atoms in water move between other atoms.  The atoms are continuously changing due to a process called protonation/deprotonation staying less than one millisecond.