WATER

we drink it, swim in it, wash ourselves with it, use it for cooking; in fact it constitute up to two-thirds of our bodies as well-indeed, no substance is as familiar to us as water. And yet this colourless, odourless fluid continues to puzzle science with its unexpected behaviour. 

water happens to be one of the smallest molecules known to us-just two atom of hydrogen and one of oxygen. Practically no chemical compound has a lighter and simpler-and yet no substance affects our planet as powerfully as this one does. It influences our weather and climate, is able to carry away high hills, carve out colossal canyons, flood might oceans and cover the land in thick sheets of ice.

And of course, without it there would be no life of any kind on earth. This colourless liquid is present in every organism-two-third of the human body is made up of water. Human can go several weeks without food, but will die in a few days without water. The same applies to most plants and animals. Whether they are bugs, birds or bunnies, trees, mushrooms or bacteria, water keeps the entire biological cycle in motion. Even the spiral DNA molecule would collapse instantly without this fluid.

water is so omnipresent that even those who have no idea whatsoever of chemistry are usually familiar with its formula H₂O - two atoms of hydrogen (H) combining with one atom of oxygen (O). And yet, this substance that we take for granted is anything but simple. Water is a curious paradox: a material that has been researched so extensively that data on it could fill entire libraries, but it also continues to present science new mysteries to puzzle over.

For this little molecule never quite behaves like other chemically comparable substances. Over the centuries researchers have discovered over 70 strange properties (called anomalies) of the H₂O molecule. To unlock its last secrets, scientists have now brought out the big guns: they are putting water under extremely high pressures, bombarding it with high-energy X-rays, forcing it through pipes 7,500 times narrower than the finest blood vessels, and simulating its behaviour on super computers.

The singular properties of this colourless, odourless and tasteless liquid are critical to many processes on our planet. If H₂O molecules looked even a tiny bit different, earth would be a lifeless desert. we all exist only because water has several special features. The most important of these are:

1. Water occurs on earth as a liquid.

2. It evaporates at a boiling point of 100^o C

3. When liquid H₂O freezes into ice, it expands.

4. Water is a perfect solvent.

5. The simple structure of this substance plays a major role in the complex biochemical processes of the body.

After centuries of research  we would like to believe that we know everything about this compound. But, as the renowned scientific journal Nature declared some time ago, "No one really understand water."