The Fascinating Facts of Water
Three fourths of the surface of our planet earth is covered with water. It is ubiquitous
( found everywhere). Then how is it fascinating? Well all living organisms owe their existence to water. That is, if there is no water no “life”, no “you”, no “me”.
So water must have some unique properties to make it responsible for the existence of all life forms. Yes it does.
Let us consider some such properties and then how they are responsible for sustaining life.
A major component of the living systems is water. About 70 % by body weight of a human is water. Just think of it, if you weigh 100 lbs, 70 lbs of that is just water. Kind of unbelievable, but can be proved quite easily. Because of its importance, water has been called as the elixir of life, a universal solvent and so on. The undeniable fact is without water, life as we know cannot exist.
The clouds over a large water body "The Lake Michigan" The frozen ice on a fence near lake Michigan (1987)
It is the only natural substance that is found in all three states of matter, liquid, solid (ice), and gas (steam, clouds) at the temperatures normally found on Earth.
What if it is otherwise?
No steam (water vapour): Think of it, if water cannot vapourise then no clouds no rain, no way of water being present on most parts of the world. It would be disastrous.No ice, would mean the arctic and antartic continents would be deprived of it, the consequences no weather changes, no temperature regulation and again disastrous.
No liquid, well I am sure you have got the idea by now.
Water has a very high surface tension.
Due to the polarity of molecules they tend to clump together in drops rather than spread out as a thin film. A property which leads to surface tension, and it is responsible for capillary action, which allows water (and the substances dissolved within) to move through the roots of plants and through the tiny blood vessels in our body.
Density of water
Water is the only liquid which exists as a liquid in a very large range of temperatures that is 0 to 100o C and it has maximum density at 4oC. Thus when water freezes (00 C) its density actually decreases because of the arrangement of water molecule into a much more open structure. So ice is capable of floating in water.
In winter when a river or lake freezes in many parts of the planet the freezing starts from the top, a vehicle can pass over the solid surface with water still remaining below and aquatic life still exists.
T /K Density g/mL
273 0.999841
274 0.999900
275 0.999941
276 0.999965 277 0.999973
Density: 1 gram per cm3 at 39.2°F, 0.95865 gram per cc at 212°F
Some helpful units in this context are.
1 gallon = 4 quarts = 8 pints = 128 ounces = 231 cubic inches
1 liter = 0.2642 gallons = 1.0568 quart = 61.02 cubic inches
1 million gallons = 3.069 acre-feet = 133,685.64 cubic feet
It is indeed fascinating to imagine what if water had started freezing from the bottom instead of the top, well think of it, it is worthwhile doing so.
Heat capacity of water is 4.182 J K-1 g-1
This is quite high compared to most other materials.
It means it takes more time to get heated up to a particular temperature, unlike most other substances and takes equally longer time to cool down too. During day time most of the solar radiation is absorbed by water surrounding the planet and night times in the absence of sunlight it is this heat absorbed which is released. Thus water acts as a moderator of temperatures. In the absence of this, day temperatures would have soared to about 200oC and night times it would have been as low as about -100oC. In this temperature range life as we know is not possible.
The suface of moon has no atmosphere and water. The side which receives sun light is very hot and the side which doesn’t is extremely cold.
The only way humans can settle on moon is to build huge green house like devices and regulate the temperature in the range it is possible for us to survive.The unique properties of water can be explained through its structure mainly "Hydrogen bonding".
Wait for the next article.