Various properties of water for many years interest scientists. Water can be in various states – firm, liquid and gaseous. At a usual average temperature water has a liquid appearance. It can be drunk, watered with it plants. Water can spread and occupy certain surfaces and take the form of those vessels in which it is. So why water liquid?
Water has special structure thanks to which takes a liquid form. It can flow, leak and drip. In crystals of solid substances there is strictly ordered structure. In gaseous substances the structure is expressed as utter chaos. Water – intermediate structure between solid and gaseous substance. Particles in structure of water are located at small distances from each other and rather ordered. But as particles are removed from each other over time, and the order of structure quickly disappears.
Forces of interatomic and intermolecular influence set average distance between particles. Molecules of water consist of atoms of oxygen and hydrogen where atoms of oxygen of one molecule are attracted to atoms of hydrogen of other molecule. unique chain of hydrogen communications which gives to water certain properties of fluidity is formed, at the same time the structure of the water is almost identical to structure of a crystal. By means of numerous experiments the fact that water itself sets to itself structure in free volume was revealed.
At compound of water with firm surfaces, the structure of water begins to unite with structure of a surface. As the structure of the adjoining water layer remains without changes, its physical and chemical properties begin to change. The viscosity of water changes. There is an opportunity to dissolve substances with a certain structure and properties. Water initially represents transparent colourless liquid. It is possible to call physical properties of water abnormal as it has quite high temperature of boiling and freezing. Water has a superficial tension. For example, it has abnormally high temperatures of freezing and boiling and also a superficial tension. Specific thresholds of evaporation and melting at water are much higher, than at any other substances. The surprising feature is that density of water is higher, than ice density that allows ice to float on a water surface. All these wonderful properties of water as liquids, are explained by existence in it again those hydrogen communications which connected molecules. The structure of a molecule of water from three atoms in a geometrical projection of a tetrahedron leads to emergence of very strong mutual attraction of molecules of water to each other. It is all about hydrogen communications of molecules, each molecule can form four absolutely identical hydrogen communications with other molecules of water. This fact also explains that water – liquid. It is no secret that fresh water on the earth the scientists think to become less and as it is possible to resolve an issue by means of chemical properties to extract fresh water. Fluid properties of water allow to find out how it is possible to change and affect water for receiving fresh, suitable for drink, waters. Water in liquid state can make energy, sate the earth, feed plants and organisms, giving the chance of life. Many events and weather depend on water and its behavior on the earth.