All theories of the origin of life on Earth are somehow related to water. She is constantly next to us, moreover, within us. The most ordinary, simple water included in the tissues of the body makes every new breath and heartbeat possible. In all these processes, it participates due to its unique properties.
What is water: definition
From a scientific point of view, the main fluid of the planet is hydrogen oxide - a binary inorganic compound. The molecular formula of water is perhaps known to all. Each structural element consists of one oxygen atom and two hydrogen atoms connected by a polar covalent bond. Under ordinary conditions, it is in a liquid state, has no taste or smell. In small volumes, plain water without impurities is colorless.
Biological role
Water is the main solvent. It is the nature of the structure of the molecule that makes this determination possible. The properties of water are related to its polarization: each molecule has two poles. Negative is associated with oxygen, and positive is associated with hydrogen atoms. A water molecule is capable of forming the so-called hydrogen bonds with particles of other substances, attracting oppositely charged atoms to its “+” and “-”. In this case, the substance, which becomes a solution, must also be polarized. One molecule of it is surrounded by several particles of water. After conversion, the substance becomes more reactive. As a solvent, water is used by all cells of living organisms. This is one of those properties that determine its biological role.
Three states
Water is known to us in three forms: liquid, solid and gaseous. The first of these aggregate states, as already mentioned, is characteristic of water under ordinary conditions. At normal atmospheric pressure and temperatures below 0 º, it becomes ice. If the heating of the substance reaches 100 º, steam is formed from the liquid.
It should be noted that substances that are similar in structure under normal conditions are in a gaseous state and have a low boiling point. The reason for the relative stability of water is the hydrogen bonds between the molecules. To transition to a state of steam, it is necessary to break them. Hydrogen bonds are strong enough, and to destroy them, requires a large amount of energy. Hence the high boiling point.
Surface tension
Due to hydrogen bonds, water has a high surface tension. In this regard, it is second only to mercury. Surface tension occurs at the boundary of two different media and requires a certain amount of energy. The result of this property is interesting effects. In zero gravity, a drop takes a spherical shape, since the liquid tends to reduce its own surface in order to save energy. Similarly, water sometimes behaves on non-wettable materials. An example is a drop of dew on the leaves. Due to the surface tension, water striders and other insects can glide along the surface of the pond.
Insulator or conductor?
In life safety classes, children are often explained that water conducts electricity well. However, this is not quite true. Due to the nature of its structure, pure water is weakly dissociated and does not conduct current. That is, in fact, it is an insulator. However, under normal conditions it is practically impossible to meet such pure water, since it dissolves many substances. And thanks to numerous impurities, the liquid becomes a conductor. Moreover, the ability to conduct electricity can determine how clean the water is.
Refraction and absorption
Another property of water, known from school to everyone, is the ability to refract light rays. Passing through the liquid, the light changes its direction somewhat. The formation of a rainbow is associated with this effect. Also, the refraction of light and our perception of it are the basis of errors in determining the depth of water bodies: it always seems smaller than it actually is.
However, the light is refracted from the visible part of the spectrum. And, for example, infrared rays are absorbed by water. That is why there is a greenhouse effect. To understand the hidden possibilities of water in this sense, we can turn to the characteristics of the atmosphere on Venus. According to one version, the evaporation of water led to the greenhouse effect on this planet.
Water color
Everyone who saw the sea or any fresh water reservoir and compared it with a liquid in a glass noticed a certain discrepancy. The color of water in a natural or artificial pond never coincides with what is observed in the cup. In the first case, it is blue, blue, even greenish-yellow, in the second it is simply absent. So what color is the water really?
It turns out that a pure liquid is not colorless. It has a light bluish tint. The color of the water is so pale that in small volumes it seems completely transparent. However, in natural conditions, it appears in all its glory. Moreover, numerous impurities, as in the case of conducting electricity, change the properties of water. Everyone met at least once a green pond or brownish puddles.
Water color and life
The color of the reservoir often depends on the microorganisms actively propagating in it, the impurities of the rocks. The greenish color of the water often indicates the presence of small algae. In the sea, areas painted in such a shade, as a rule, abound in animals. Therefore, fishermen always pay attention to what color the water is. Pure blue waters are poor in plankton and, therefore, those who feed on it.
Sometimes microorganisms give the most bizarre shades. There are lakes with chocolate-colored water. The activity of unicellular algae and bacteria has made a turquoise pond on the island of Flores in Indonesia.
In Switzerland, on the Sanetsch Pass, there is a lake with bright pink water. The pond in Senegal has a slightly paler shade.
Multi-colored miracle
A striking sight appears before tourists in America, in Yellowstone National Park. Here is the Morning Glory Lake. Its waters have a pure blue color. The reason for this shade is all the same bacteria. Yellowstone is famous for its many geysers and hot springs. At the bottom of Lake Morning Glory there is a narrow volcano vent. The heat rises from there and maintains the temperature of the water, as well as the development of bacteria. Once the whole lake was crystal blue. However, over time, the mouth of the volcano became clogged, which was also facilitated by tourists throwing coins and other garbage with their love. As a result, the surface temperature decreased; other types of bacteria began to multiply here. Today, the color of water changes with depth. At the bottom of the lake is still saturated blue.
Several billion years ago, water contributed to the emergence of life on Earth. Since then, its value has not diminished in the least. Water is necessary for a number of chemical reactions that occur at the cellular level, it is part of all tissues and organs. The oceans cover about 71% of the planet’s surface and play a huge role in maintaining the stability of the state of such a gigantic system as the Earth. The physical and chemical properties of water make it possible to call it the main substance for all living things. Ponds, being the habitat of multicellular microorganisms, in addition, become a source of beauty and inspiration, demonstrate the huge creative abilities of nature.