Water occupied about 70% of the Earth's surface. It is the share of each inhabitant of our planet about 0.008 km3 fresh and 0.33 km3 sea water. Solid water — ices and snow — covered nearly 20% of sushi.
Water is one of the best solvents and represents hydrogen oxide with a chemical formula of H2O. Under usual conditions this substance is capable to interact with many oxides, the main or acid and also with alkaline metals.
If whether at water taste and a smell
Water can exist in three aggregate states: firm, liquid, gaseous. And in one of these states it smells of nothing at all. Water, ice or steam and any taste have no.
It is considered that some vertebrata began to smell waters are capable to feel. But the olfactory system of the person does not react to this substance in any way.
The distilled water, thus, has no taste and a smell. However in the nature in pure form this substance practically does not meet. As water is good solvent, at it there are always various impurity.
As scientists managed to find out, the water drain by land annually takes out about 50 million tons of different substances to oceans and the seas. At the same time there is at natural water usually not only a set of salts, but also huge amount of various organic impurity.
The decaying plants give to water in lakes, the rivers and ponds an ooze smell. Also natural water can smell, for example, of the earth and a mold. Occurs so at its infection with fungi or microorganisms. At non-compliance with standards of environmental safety by the industrial enterprises, water in ponds, lakes and the rivers, close to them, can get a chemical or medicinal smell.
Chlorine, contrary to widespread opinion, at the correct use for disinfection does not give any smell or foreign smack to water. However this substance is capable to react with many types of the elements dissolved in water therefore the characteristic smell of "bleaching powder" appears.
Bipolyarna water molecules and therefore unite in groups with emergence of strong hydrogen connection. Energy to break this link, it is required much.
Because of bipolarity of molecules water has rather high temperature of boiling. Without hydrogen communications it would be equal not 100 °C, but only 80 °C.
The solid form of almost each substance has big density, than liquid. Water in this plan is an exception. After freezing its volume increases almost by 8%. For this reason in reservoirs ice does not sink, and always floats on a surface.