Water, in its purest form of one oxygen to two hydrogen atoms (H₂O for the technically minded), is a transparent, odourless*, tasteless*, liquid. It's apparently quite important since it can make up to three quarters of a human's* bodyweight and accounts for 70.7 % of the surface area of Earth itself.

Water freezes at 0° C (32° F) and boils at 100° C (212° F), at least at sea-level*, and has a number of useful properties

1. Water has a high heat capacity: It absorbs and releases large amounts of heat before its temperature changes appreciably.
2. Water is an excellent solvent: though it is not the universal solvent sometimes claimed small, reactive chemicals such as salts, acids and bases dissolve easily in water and become evenly distributed.
3. Water is a reactant

Ice

A curious property of water is what happens when you freeze it. In general as you freeze something its volume decreases due to the reduction of kinetic energy of the atoms. In the case of water, however, ice is actually larger in volume due to the arrangement of atoms.

Uses for water

Water is quite a useful substance but due to its range of uses you may not be getting the most out of your water. To help, here is a list of some uses for water.

• You can bathe in it.
• You can squirt it at fires to put them out.*
• You can squirt it at people for entertainment (for example Wet T-shirt competitions).
• You can freeze it to put in drinks
• You can use it as a mixer in drinks.
• If you have enough of the frozen water you can make an Igloo with it.
• You can shave the frozen water to make the base substance for ice water.
• You can bottle it to sell to people.
• You can boil it to produce steam to give enough pressure to drive a locomotive, or produce a cute whistle on your kettle.
• You can stick it in a glass to absorb those nasty microwaves in your microwave oven.
• You can use that boiled water to make coffee or Tea.
• You can swim in it.
• You can sit in it while a pump blows bubbles of air through it.
• You can sweat in it in a steam room.
• You can dissolve things in it to produce different food (for example, Jelly) or drink items.
• You can dissolve things in it to produce a mixture to clean other things.
• You can dissolve things in it to use on an oil burner for aromatherapy purposes, or to rid the house of that smell.
• You can squirt it from small nozzles to produce impressive displays.
• You can fill it with carbon-dioxide to produce Soda Water to use as a mixer in drinks.
• You can put minerals in it to produce mineral water.
• You can spray it on things to cool them down.
• You can cut things with it if you spray it fast enough.
• You can run it through turbines to produce electricity.
• You can run from it when it starts to rain.
• You can swear at it when you've just put the clothes out to dry and it begins to fall from the sky.
• You can make plants grow with it*.
• You can use it as part of a hangover cure.
• In extreme emergencies you can drink it.

Heavy Water

This is a type of water where the hydrogen atoms (one Proton in the nucleus) are replaced by deuterium atoms (one Proton and one Neutron in the nucleus). It's used chiefly as a source of deuterons for experiments in nuclear physics.