Introduction…………………………………………………………………….3

Main part

1. Properties of water……………………………………………………………5

2. The structure of the water molecule……………………………………………….10

Conclusion……………………………………………………………………12

Bibliography……………………………………………………………… 13

Application……………………………………………………………………14

Introduction

Water is one of the most common substances in nature (the hydrosphere occupies 71% of the Earth's surface). Water plays an important role in the geology and history of the planet. Living organisms cannot exist without water. The fact is that the human body is almost 63% - 68% water. Almost all biochemical reactions in every living cell are reactions in aqueous solutions. In solutions (mainly aqueous), most technological processes take place at the enterprises of the chemical industry, in the production of medicines and food products. And in metallurgy, water is extremely important, and not only for cooling. It is no coincidence that hydrometallurgy - the extraction of metals from ores and concentrates using solutions of various reagents - has become an important industry.

Water is a common and unusual substance. The well-known Soviet scientist Academician I. V. Petryanov called his popular science book about water "the most extraordinary substance in the world." And "Entertaining Physiology", written by B.F. Sergeev, Doctor of Biological Sciences, begins with a chapter on water - "The substance that created our planet."

Scientists are absolutely right: there is no substance on Earth that is more important for us than ordinary water, and at the same time there is no other such substance, in the properties of which there would be as many contradictions and anomalies as in its properties.

Almost ⅔ of the surface of our planet is occupied by oceans and seas. hard water- snow and ice - 20% of the land is covered. The planet's climate depends on water. Geophysicists say that the Earth would have cooled down long ago and turned into a lifeless piece of stone, if not for water. She has a very high heat capacity. When heated, it absorbs heat; cooling down, gives it away. Terrestrial water both absorbs and returns a lot of heat and thus “evens out” the climate. And the Earth is protected from cosmic cold by those water molecules that are scattered in the atmosphere - in clouds and in the form of vapors ...

Water properties

The most fully studied properties of water, thanks to which life arose. These properties made possible the existence of wildlife in the temperature range that is characteristic of the Earth as a cosmic body.
What are these properties?

Density of water.

One of the most important properties of water is its density. Fresh water has its maximum density at 4 °C. At this temperature, one kilogram of water occupies the minimum volume (Fig. 1). When the temperature drops from 4 ° C to 0, the density decreases, i.e., water with a temperature of 4 ° C is at the bottom, and colder water rises to the top, where it freezes, turning into ice.

Density ordinary ice- solid crystalline phase of water - less than the density of water, so the ice floats on the surface, protecting the water from further cooling. It acts as an ice "coat" that protects the freshwater object from complete freezing. Thus, conditions are formed for the life of the inhabitants of reservoirs at low temperatures.

AT sea ​​water a significant amount of salts are dissolved, and it behaves completely differently when cooled. Its freezing temperature depends on salinity, but on average it is -1.9°C. The maximum density of such water is at a temperature of -3.5°C. Sea water turns into ice before reaching its maximum density. Therefore, vertical mixing of sea water occurs when it is cooled from the positive temperature to the freezing temperature. Thanks to this circulation, the lower horizons of the ocean are enriched with oxygen, and water rich in nutrients enters the upper layers from the lower ones. It should be noted that both sea and fresh ice is lighter than water and floats on its surface, protecting the deep layers of water in the seas and oceans from direct contact with cold air masses and thereby contributing to the conservation of heat. At the same time, various modifications of ice were obtained artificially at high pressure. Some of them are heavier than water, others melt and, therefore, freeze at high temperatures. This is the so-called "hot ice". Therefore, we are all lucky not only with the presence of water on Earth and solar radiation, but also with atmospheric pressure. Otherwise, the whole Earth could be bound by an ice shell.

Thermodynamic constants of water.

Water has special, anomalous properties. First of all, this concerns such thermodynamic constants as the heat capacity of water, the heat of vaporization, and the latent heat of ice melting. The anomalous nature of these quantities determines most of the physicochemical and biological processes on Earth.

The specific heat capacity of water is 4.1868 kJ / (kg-K), which is almost twice the specific heat capacity of substances such as ethanol(2.847), vegetable oil (2.091), paraffin (2.911) and many others. And this means that when heated by the same number of degrees, water is able to absorb almost twice as much heat as the listed liquids. But even when cooling, water gives off more heat than other liquids. Therefore, when the waters of the World Ocean are heated under the influence of sunlight and they cool down in the absence of solar radiation energy, the heat capacity acts as a property that ensures minimal fluctuations in water temperature day and night, summer and winter.

The heat of vaporization of water has an abnormally high value. This value is more than twice the heat of vaporization of ethanol, sulfuric acid, aniline, acetone and other substances. Therefore, even in the hottest time, water evaporates extremely slowly, which contributes to its conservation and, consequently, the preservation of life on Earth.

high value latent heat ice melting also ensures the stability of the temperature regime on the planet.
One of the interesting properties of water is that its lowest heat capacity is at a temperature of 37 ° C, which means that at this temperature, minimal energy costs are required to change it. This is probably why the body temperature of warm-blooded creatures is close to this value.

Water has anomalously high values ​​of other constants as well. Substances formed by the combination of hydrogen with those in the same row periodic table oxygen, sulfur, selenium, tellurium, are called hydrides. The oxygen hydride is called water. The unusual properties of oxygen hydride, in comparison with the properties of other hydrides, lies in the fact that, unlike them, water under normal conditions (at normal pressure and temperature from 0 to 100 ° C) is in a liquid state, and not in a gaseous state. If water did not have anomalous boiling and freezing temperatures, then these processes would occur at much lower negative temperatures, and liquid water would be present on colder planets. And therefore, there would be no life on Earth.

The force of the surface tension of water.

There are other special properties of water that allow us to call it a truly amazing compound. This is the surface tension of a liquid. The forces of interaction of the molecules that make up water attract them to each other, and breaking this bond is not so easy. Most people know the school experience, when a needle carefully placed in a saucer of water floats on the surface. Many have seen an interesting trick when in full glass the waters lower a significant number of coins and the water, without overflowing, rises in a small dome. Finally, there is a biblical legend about how Christ walked on water. All these phenomena and legends are connected with the high surface tension of water. Due to surface tension, water rises through the capillary channels in the soil to the surface of the Earth, enters the tissues and cells of plants and living organisms. Of all known liquids, only mercury has a higher surface tension than water.
Very famous interesting feature water, associated with the propagation of sound waves in it. The speed of sound propagation in water is anomalously high, it exceeds the speed of its propagation in air by almost 6 times.

properties of pure water.

Pure water is a clear, colorless and odorless liquid. At a pressure of 1 atm, water freezes at 0 and boils at 100°C. When the pressure is doubled, water boils at a temperature of 120 ° C, and when it is halved, at 81 ° C. However, as the pressure decreases, the melting point of ice (or the freezing point of water) rises. At low pressures, water can exist only in the form of ice or steam, and at high temperatures - only in the form of steam. There are also critical values ​​for water pressure and temperature. At pressures over 22.1 atm. and temperatures above 374.4 ° C, the difference between liquid and vapor disappears. Water exists in a gaseous state.

Amazing values ​​of atmospheric pressure and temperature have developed on Earth, since it is at these values ​​that water is present on the planet in liquid form, ensuring the development of all existing life forms. With these parameters, oxygen is dissolved in water, which is necessary for the life of aquatic organisms, as well as for the processes of self-purification of water. For many millennia, the presence of the atmosphere, hydrosphere and solar radiation created an insignificant temperature difference in summer and winter, day and night, providing conditions for the existence of life.

The ability of water to dissolve.

However, the most amazing feature of water is its ability to dissolve other substances. The ability of substances to dissolve depends on their dielectric constant. The higher it is, the more the substance is capable of dissolving others. So, for water, this value is 9 times higher than for air or vacuum. Therefore, fresh or clean waters are practically not found in nature. Something is always dissolved in the earth's water. It can be gases, molecules or ions chemical elements. It is believed that all elements of the table can be dissolved in the waters of the oceans. periodic system elements, at least to date, more than 80 of them have been discovered.

The structure of the water molecule

These two elements - hydrogen and oxygen - are antagonists. One of them dominates in space, the other - on Earth. One (hydrogen) seeks to donate a single electron of its electron shell, and the other (oxygen) seeks to get two electrons from other chemical elements.

Analyzing the composition of a water molecule, we can say that two hydrogen atoms and one oxygen atom “found each other” in it. Thus, in the composition of water, the chemical formula of which is written as H2 0, nine different stable types of water can theoretically be present (the number of permutations from 5 to 3) However, 99.97% of all water is represented in the hydrosphere plain water type 1 H216 0. The proportion of heavy water 2 H216 0 is less than 0.02%.

modern science Several models are known that can be used to resolve many of the anomalous properties of water. It is believed that some properties are determined by the number of associations of molecules of monomers (Н2О)1, dimers (Н2О)2 and trimers (Н2О)3, which are predominantly present in water at various temperatures.
So, at a temperature of about 0 in water there are mainly trimers, at a temperature of about 4 ° C - dimers, and in a gaseous state, water contains mainly monomers. Sometimes these associations are called trihydrols.

Some scientists propose to consider water as a set of associations of molecules, including from one to eight molecules in each association. Others believe that the structure of water is a spatial "lace" formed by various "shimmering clusters" (Fig. 2). Still others propose to study the properties of water, taking into account the structural features of its molecule, which, in turn, are determined by the features of the elements that make up the water molecule. According to modern concepts, the water molecule is like a small magnet.

Why are there solutes in water?
The Danish scientist N. Bjerrum in 1951 proposed a model of the water molecule with a point charge distribution. In accordance with modern concepts, a water molecule is a tetrahedron (or pyramid, (Fig. 3), in the middle of which the center of the molecule is located, and in the corners - electric charges.

Two positive charges correspond to two hydrogen atoms, each of which "provided" its electrons to the oxygen atom, and m negative charges corresponding to the "unpaired" electrons of oxygen. Thus, the water molecule is a dipole, one of the poles of which has a positive charge, and the other is negative. The poles of the dipole are separated by a certain distance, therefore, in the electrostatic field, the water dipole unfolds along the lines of tension electric field. If the electrostatic field is formed by a negatively charged ion, then the water dipole turns to this ion with its positive pole, and vice versa. The properties of water as a solvent are largely determined by the polarized structure of its molecule. The high polarity of molecules is the reason for the activity of water during chemical interactions, when salts, acids and bases are dissolved in it, i.e., during the formation of electrolytes. Water is able to dissolve many substances, creating with them homogeneous physico-chemical systems of variable composition. Salts dissolved in natural waters are in an ionic state, i.e. subjected to electrolytic dissociation.

Conclusion

During the course work, the properties and structure of the water molecule were considered. Water is an ordinary substance at first glance, but if we look at it in more detail, we can find out a lot of interesting and unusual things. Firstly, water is the source of life on Earth, if there were no water, then life would not have arisen. Secondly, the properties that water possesses are not possessed by more than one substance. Water can be in three states of aggregation, at a certain temperature. Water can also take in and give off heat, and will evaporate more slowly than other substances. Moreover, in water can spread sound waves and at a very high speed. But the most amazing property of water is the ability to dissolve other substances.

As for the structure of water, it is also unique in its own way. Water consists of two hydrogen atoms and one oxygen atom, we can say that these atoms just found each other. But scientists still cannot unravel all the structural features of this amazing substance, and much remains a mystery to us all.

This is what ordinary matter looks like at first glance. But no one thought about the fact that when every day he encounters water, that this is such an unlikely and very unusual substance that contains a lot of unsolved mysteries. But we cannot fully unravel them, this is all the unusualness and peculiarity of water, without which we would never have been born.

Bibliography

1. Akhmetov N.S., Inorganic chemistry. M., 2001

2. Glinka N.L., general chemistry. St. Petersburg, 2003

3. Knunyants I. L., Chemical encyclopedia. Volume 1. M., 2002

4. Petryanov IV, The most unusual substance in the world. M., 2005

5. Khomchenko G.P., Chemistry for applicants to universities. M., 2002

Application

Water is the source of life on Earth, a great natural value that covers 71% of the surface of our planet, the most common chemical compound and the necessary basis for the existence of all life on the planet. High content in plants (up to 90%) and in the human body (about 70%) only confirms the importance of this component, which has no taste, smell or color.

Water is life!

The role of water in human life is invaluable: it is used for drinking, food, washing, various household and industrial needs. Water is life!

The role of water in human life can be determined by its share in the body and organs, each cell of which is rich in an aqueous solution of essential nutrients. Water is one of effective means physical education, widely used for personal hygiene, recreational physical education, hardening, water sports.

Biochemical properties of water

Maintaining the elasticity and volume of a living cell would be impossible without water, as well as a significant part of chemical reactions organisms that occur in aqueous solutions. Such a valuable liquid is indispensable for its thermal conductivity and heat capacity, which provides thermoregulation and protects against temperature extremes.

Water in human life is able to dissolve some acids, bases and salts, which are ionic compounds and some polar non-ionic formations (simple alcohols, amino acids, sugars), called hydrophilic (from Greek literally - a tendency to moisture). Nucleic acids, fats, proteins and some polysaccharides are hydrophobic substances (from Greek - fear of moisture) beyond the power of liquid.

biological significance water is quite large, since this priceless liquid is the main medium for internal processes occurring in the body. In percentage terms, the presence of water in the body is as follows:

Body systems
Adipose tissue

The statement of the science fiction writer V. Savchenko, who revealed the meaning of water in one phrase, is interesting on this occasion: a person has much more motives to consider himself a liquid, in contrast, for example, to a 40% sodium solution. And among biologists, a joke is popular that water “invented” a person as a means of its own transportation, the main component of whose body it is. 2/3 of her total contained inside the cells and is called "intracellular", or "structured" fluid, which is able to provide the body's resistance to the influence of negative environmental factors. The third part of the water is outside the cells, and 20% of this amount is the intercellular fluid itself, 2% and 8% - respectively, the water of the lymph and blood plasma.

Importance of water in human life

Meaning natural component in life and everyday life is simply invaluable, since without it existence is impossible in principle.

Water is essential for life because:

• humidifies the inhaled oxygen;
• helps the body in the qualitative assimilation of nutrients;
• contributes to the conversion of food into energy and normal digestion;
• participates in passing metabolism and chemical reactions;
• removes excess salts, toxins and toxins;
• regulates body temperature;
• provides skin elasticity;
• regulates blood pressure;
• prevents the formation of kidney stones;
• is a kind of "lubricant" for the joints and a shock absorber for the spinal cord;
• protects vital organs.

The water cycle in the body

One of the conditions for the existence of all living things is the constant content of water, the amount of which enters the body depends on the lifestyle of a person, his age, physical health, and environmental factors. During the day, up to 6% of the water available in the body is exchanged; half of its total amount is updated within 10 days. So, per day the body loses about 150 ml of water with feces, about 500 ml with exhaled air and the same amount with sweat and 1.5 liters is excreted in the urine. Approximately the same amount of water (about 3 liters per day) a person receives back. Of these, a third of a liter is formed in the body itself during biochemical processes, and about 2 liters are consumed with food and drinks, and the daily requirement for exclusively drinking water is about 1.5 liters.

AT recent times experts have calculated that a person should still drink about 2 liters of pure water per day in order to prevent even the slightest dehydration of the body. The same amount is recommended to be consumed by yogis who know the true meaning of air and water. An absolutely healthy human body should ideally have a state of water balance, otherwise called water balance.

By the way, German scientists, after a series of experiments conducted on students, found out that those who drink water and drinks more than others show greater restraint and a penchant for creativity. Water in human life plays an incentive role, filling with energy and vitality.

According to some estimates, for 60 years of life a person on average drinks about 50 tons of water, which is commensurate with almost a whole tank. It is interesting to know that ordinary food is half water: in its meat - up to 67%, in cereals - 80%, vegetables and fruits contain up to 90%, bread - about 50%.

High Water Consumption Situations

Usually a person receives about 2-3 liters of water per day, but there are situations in which the need for it increases. It:

• Increased body temperature (more than 37 ° C). With each increasing degree of water, 10% more of the total is required. .
• Heavy physical work in the fresh air, in which you need to drink 5-6 liters of liquid.
• Work in hot shops - up to 15 liters.

Deficiency of valuable fluid is the cause of many diseases: allergies, asthma, overweight, high blood pressure, emotional problems (including depression), and its absence leads to disruption of all body functions, undermining health and making vulnerable to disease.

Loss of water up to 2% of the total body weight (1 - 1.5 liters) will cause a person to feel thirsty; loss of 6 - 8% will lead to a semi-conscious state; 10% will cause the appearance of hallucinations and impaired swallowing function. Deprivation of 12% of water from the total body weight will lead to death. If without food a person is able to survive for about 50 days, subject to the consumption of drinking water, then without it - a maximum of 5 days.

In fact, most people drink less than the recommended amount of water: only a third, and the ailments that appear are not at all associated with a lack of fluid.

Signs of lack of water in the body

The first signs of dehydration:

A stable supply of water to the body required quantity helps to ensure vitality, get rid of ailments and many serious diseases, improve thinking and coordination of the brain. Therefore, the emerging thirst should always be tried to quench. It is better to drink little and often at the same time, since a large amount of liquid for the purpose of a one-time replenishment of the daily norm will be completely absorbed into the blood, which will give a noticeable load on the heart until the water is removed from the body by the kidneys.

Water balance of the body - a direct path to health

In other words, water in human life, with a properly organized drinking regime, can create acceptable conditions for maintaining the necessary water balance. It is important that the liquid is of high quality, with the presence of the necessary minerals. The situation of the modern world is paradoxical: water, the source of life on Earth, can be dangerous for life itself, carrying various infections with almost every drop. That is, only pure water can be useful for the body, the quality problem of which is modern world very relevant.

Water scarcity is a scary future for the planet

Rather, the very problem of the availability of drinking water becomes vitally important, every day turning into an increasingly scarce product. Moreover, the importance of water on Earth and its lack in international relations are discussed at highest level and often in a conflicting way.

Now more than 40 countries are experiencing water shortages due to the aridity of many regions. In 15 - 20 years, even according to the most optimistic forecasts, every person will understand the importance of water on Earth, since the problem of its shortage will affect 60 - 70% of the planet's population. AT developing countries water deficit will increase by 50%, in developed countries - by 18%. As a result, international tensions around the topic of shortages will increase. water resources.

Polluted water as a result of human activity

This is due to geophysical conditions, human economic activity, often ill-conceived and irresponsible, which significantly increases the burden on water resources and leads to their pollution. A huge amount of water goes to the needs of cities and industry, which not only consume, but also pollute water, dumping about 2 million tons of waste into water bodies every day. The same goes for agriculture, where millions of tons of waste products and fertilizers flow into waterways from farms and fields. In Europe, out of 55 rivers, only 5 are considered clean, while in Asia, all rivers are extremely littered with agricultural waste and metals. In China, 550 out of 600 cities are experiencing water shortages; due to severe pollution, fish do not survive in water bodies, and some rivers that flow into the ocean simply do not reach it.

What flows from the taps

And why go far if the quality of water, which leaves much to be desired, concerns almost every person. The importance of water in human life is great, this is especially true when it is consumed, when sanitary standards go against the quality of the consumed liquid, which contains pesticides, nitrites, oil products, and salts that are harmful to health. heavy metals. Half of the population receives hazardous water, which causes about 80% of all known diseases.

Chlorine is dangerous!

To avoid possible infection with any infection, the water is chlorinated, which in no way diminishes the danger. On the contrary, chlorine, which destroys many dangerous microbes, forms unhealthy chemical compounds and provokes diseases such as gastritis, pneumonia, oncology. When boiled, it does not have time to dissolve completely and combines with the always present in water. organic matter. In this case, dioxins are formed - very dangerous poisons, surpassing even potassium cyanide in their strength.

Water poisoning is much worse than food poisoning, because water in human life, unlike food, takes part in all biochemical processes organism. Dioxins accumulated in the body decompose very slowly, almost tens of years. Causing disorders of the endocrine system, reproductive functions, they destroy the immune system, cause cancer and genetic abnormalities. Chlorine is the most dangerous killer of our time: killing one disease, it gives rise to another, even worse. After global water chlorination began in 1944, epidemics of heart disease, dementia and cancer began to appear massively. The risk of cancer is 93% greater than that of those who drink non-chlorinated water. There is only one conclusion: tap water should never be drunk. The ecological significance of water is the No. 1 problem in the world, since if there is no water, there will be no life on Earth. Therefore, an indispensable condition for maintaining health is its cleaning and compliance with sanitary and epidemiological standards.

Water (hydrogen oxide) is a transparent liquid that has no color (in a small volume), smell and taste. Chemical formula: H2O. AT solid state is called ice or snow, and in gaseous - water vapor. About 71% of the Earth's surface is covered with water (oceans, seas, lakes, rivers, ice at the poles).

It is a good highly polar solvent. AT natural conditions always contains dissolved substances (salts, gases). Water is of key importance in the creation and maintenance of life on Earth, in the chemical structure of living organisms, in the formation of climate and weather.

Almost 70% of the surface of our planet is occupied by oceans and seas. Solid water - snow and ice - covers 20% of the land. Of the total amount of water on Earth, equal to 1 billion 386 million cubic kilometers, 1 billion 338 million cubic kilometers are accounted for by salt water oceans, and only 35 million cubic kilometers are fresh waters. The total amount of ocean water would be enough to cover it Earth layer over 2.5 km. For each inhabitant of the Earth, there are approximately 0.33 cubic kilometers of sea water and 0.008 cubic kilometers of fresh water. But the difficulty is that the vast majority of fresh water on Earth is in a state that makes it difficult for humans to access. Almost 70% of fresh water is contained in the ice sheets of the polar countries and in mountain glaciers, 30% is in aquifers underground, and only 0.006% of fresh water is simultaneously contained in the channels of all rivers. Water molecules have been found in interstellar space. Water is part of comets, most planets solar system and their companions.

The composition of water (by mass): 11.19% hydrogen and 88.81% oxygen. Pure water is clear, odorless and tasteless. It has the highest density at 0°C (1 g/cm3). The density of ice is less than the density of liquid water, so ice floats to the surface. Water freezes at 0°C and boils at 100°C at a pressure of 101,325 Pa. It is a poor conductor of heat and a very poor conductor of electricity. Water is a good solvent. The water molecule has an angular shape; hydrogen atoms form an angle of 104.5° with respect to oxygen. Therefore, the water molecule is a dipole: that part of the molecule where hydrogen is located is positively charged, and the part where oxygen is located is negatively charged. Due to the polarity of water molecules, electrolytes in it dissociate into ions.

In liquid water, along with ordinary H20 molecules, there are associated molecules, i.e., combined into more complex aggregates (H2O)x due to the formation of hydrogen bonds. The presence of hydrogen bonds between water molecules explains the anomalies of its physical properties: maximum density at 4 ° C, high boiling point (in the series H20-H2S - H2Se) anomalously high heat capacity. As the temperature rises, hydrogen bonds break, and a complete break occurs when water changes into steam.

Water is a highly reactive substance. Under normal conditions, it interacts with many basic and acidic oxides, as well as with alkali and alkaline earth metals. Water forms numerous compounds - crystalline hydrates.

Obviously, water-binding compounds can serve as desiccants. Other drying agents include P205, CaO, BaO, metallic Ma (they also chemically interact with water), and silica gel. To important chemical properties water is its ability to enter into reactions of hydrolytic decomposition.

Physical properties of water.

Water has a number of unusual features:

1. When ice melts, its density increases (from 0.9 to 1 g/cm³). For almost all other substances, the density decreases when melted.

2. When heated from 0 °C to 4 °C (more precisely, 3.98 °C), water contracts. Accordingly, as it cools, the density decreases. Thanks to this, fish can live in freezing waters: when the temperature drops below 4 ° C, more cold water as the less dense one remains on the surface and freezes, while a positive temperature remains under the ice.

3. High temperature and specific heat melting point (0 °C and 333.55 kJ/kg), boiling point (100 °C) and specific heat of vaporization (2250 kJ/kg), compared to hydrogen compounds of similar molecular weight.

4. High heat capacity of liquid water.

5. High viscosity.

6. High surface tension.

7. Negative electric potential of the water surface.

All these features are associated with the presence of hydrogen bonds. Due to the large difference in the electronegativity of hydrogen and oxygen atoms, electron clouds are strongly shifted towards oxygen. Due to this, as well as the fact that the hydrogen ion (proton) does not have internal electron layers and has small dimensions, it can penetrate into electron shell negatively polarized atom of the neighboring molecule. Due to this, each oxygen atom is attracted to the hydrogen atoms of other molecules and vice versa. A certain role is played by the proton exchange interaction between and within water molecules. Each water molecule can participate in a maximum of four hydrogen bonds: 2 hydrogen atoms - each in one, and an oxygen atom - in two; in this state, the molecules are in an ice crystal. When ice melts, some of the bonds break, which allows the water molecules to be packed more densely; when water is heated, the bonds continue to break, and its density increases, but at temperatures above 4 ° C, this effect becomes weaker than thermal expansion. Evaporation breaks all remaining bonds. Breaking bonds requires a lot of energy, hence the high temperature and specific heat of melting and boiling and high heat capacity. The viscosity of water is due to the fact that hydrogen bonds prevent water molecules from moving at different speeds.

For similar reasons, water is a good solvent for polar substances. Each solute molecule is surrounded by water molecules, and the positively charged parts of the solute molecule attract oxygen atoms, and the negatively charged parts attract hydrogen atoms. Because the water molecule is small, many water molecules can surround each solute molecule.

This property of water is used by living beings. In a living cell and in the intercellular space, solutions interact various substances in water. Water is necessary for the life of all unicellular and multicellular living beings on Earth without exception.

Pure (free of impurities) water is a good insulator. Under normal conditions, water is weakly dissociated and the concentration of protons (more precisely, hydronium ions H3O+) and hydroxide ions HO− is 0.1 µmol/l. But since water is a good solvent, certain salts are almost always dissolved in it, that is, positive and negative ions are present in water. As a result, water conducts electricity. The electrical conductivity of water can be used to determine its purity.

Water has a refractive index n=1.33 in the optical range. However, it strongly absorbs infrared radiation, and therefore water vapor is the main natural greenhouse gas responsible for more than 60% of the greenhouse effect. Due to the large dipole moment of the molecules, water also absorbs microwave radiation, on which the principle of the microwave oven is based.

aggregate states.

1. According to the state, they distinguish:

2. Solid - ice

3. Liquid - water

4. Gaseous - water vapor

Fig.1 "Types of snowflakes"

At atmospheric pressure, water freezes (turns into ice) at 0°C and boils (turns into water vapor) at 100°C. As the pressure decreases, the melting point of water slowly rises and the boiling point falls. At a pressure of 611.73 Pa (about 0.006 atm), the boiling and melting points coincide and become equal to 0.01 ° C. This pressure and temperature is called the triple point of water. At lower pressures, water cannot be in a liquid state, and ice turns directly into steam. The sublimation temperature of ice decreases with decreasing pressure.

With an increase in pressure, the boiling point of water increases, the density of water vapor at the boiling point also increases, and liquid water decreases. At a temperature of 374 °C (647 K) and a pressure of 22.064 MPa (218 atm), water passes the critical point. At this point, the density and other properties of liquid and gaseous water are the same. At higher pressures, there is no difference between liquid water and water vapor, hence no boiling or evaporation.

Metastable states are also possible - supersaturated vapor, superheated liquid, supercooled liquid. These states can exist for a long time, but they are unstable and a transition occurs upon contact with a more stable phase. For example, it is not difficult to obtain a supercooled liquid by cooling clean water in a clean vessel below 0 °C, however, when a crystallization center appears, liquid water quickly turns into ice.

Isotopic modifications of water.

Both oxygen and hydrogen have natural and artificial isotopes. Depending on the type of isotopes included in the molecule, the following types of water are distinguished:

1. Light water (just water).

2. Heavy water (deuterium).

3. Superheavy water (tritium).

Chemical properties of water.

Water is the most common solvent on Earth, largely determining the nature of terrestrial chemistry as a science. Most of chemistry, at its inception as a science, began precisely as the chemistry of aqueous solutions of substances. It is sometimes considered as an ampholyte - both an acid and a base at the same time (cation H + anion OH-). In the absence of foreign substances in water, the concentration of hydroxide ions and hydrogen ions (or hydronium ions) is the same, pKa ≈ approx. 16.

Water itself is relatively inert under normal conditions, but it is strongly polar molecules solvate ions and molecules, form hydrates and crystalline hydrates. Solvolysis, and in particular hydrolysis, occurs in animate and inanimate nature, and is widely used in the chemical industry.

Chemical names for water.

From a formal point of view, water has several different correct chemical names:

1. Hydrogen oxide

2. Hydrogen hydroxide

3. Dihydrogen monoxide

4. Hydroxy acid

5. English hydroxic acid

6. Oxidane

7. Dihydromonoxide

Types of water.

Water on Earth can exist in three main states - liquid, gaseous and solid, and, in turn, acquire a variety of forms, which are often adjacent to each other. Water vapor and clouds in the sky, sea water and icebergs, mountain glaciers and mountain rivers, aquifers in the earth. Water is able to dissolve many substances in itself, acquiring one or another taste. Because of the importance of water, "as a source of life," it is often divided into types.

Characteristics of waters: according to the peculiarities of origin, composition or use, they distinguish, among other things:

1. Soft water and hard water - according to the content of calcium and magnesium cations

2. Groundwater

3. Melt water

4. Fresh water

5. Sea water

6. Brackish water

7. Mineral water

8. Rain water

9. Drinking water, Tap water

10. Heavy water, deuterium and tritium

11. Distilled water and deionized water

12. Waste water

13. Storm water or surface water

14. By isotopes of the molecule:

15. Light water (just water)

16. Heavy water (deuterium)

17. Super heavy water (tritium)

18. Imaginary water (usually with fabulous properties)

19. Dead water - a type of water from fairy tales

20. Living water - a kind of water from fairy tales

21. Holy water - a special kind of water according to religious teachings

22. Polivoda

23. Structured water is a term used in various non-academic theories.

World water reserves.

The huge layer of salt water that covers most of the Earth is a single whole and has a roughly constant composition. The oceans are huge. Its volume reaches 1.35 billion cubic kilometers. It covers about 72% of the earth's surface. Almost all water on Earth (97%) is in the oceans. Approximately 2.1% of the water is concentrated in polar ice and glaciers. All fresh water in lakes, rivers and groundwater is only 0.6%. The remaining 0.1% of the water is part of the saline water from wells and saline waters.

The 20th century is characterized by an intensive growth of the world's population and the development of urbanization. Giant cities with a population of more than 10 million people appeared. The development of industry, transport, energy, industrialization of agriculture have led to the fact that the anthropogenic impact on the environment has assumed a global character.

Increasing the effectiveness of measures to protect the environment is associated primarily with the widespread introduction of resource-saving, low-waste and non-waste technological processes, and a decrease in air and water pollution. Environmental protection is a very multifaceted problem, which is dealt with, in particular, by engineering and technical workers of almost all specialties that are associated with economic activities in settlements and industrial enterprises, which can be a source of pollution mainly of air and water.

Water environment. The aquatic environment includes surface and ground waters.

surface water mainly concentrated in the ocean, containing 1 billion 375 million cubic kilometers, about 98% of all water on Earth. The surface of the ocean (water area) is 361 million square kilometers. It is about 2.4 times the land area of ​​the territory, which occupies 149 million square kilometers. The water in the ocean is salty, and most of it (more than 1 billion cubic kilometers) retains a constant salinity of about 3.5% and a temperature of approximately 3.7oC. Noticeable differences in salinity and temperature are observed almost exclusively in the surface water layer, as well as in the marginal and especially in the Mediterranean seas. The content of dissolved oxygen in water decreases significantly at a depth of 50-60 meters.

Groundwater can be saline, brackish (lower salinity) and fresh; existing geothermal waters have an elevated temperature (over 30 °C). For the production activities of mankind and its household needs, fresh water is required, the amount of which is only 2.7% of the total volume of water on Earth, and a very small share of it (only 0.36%) is available in places that are easily accessible for extraction. Most of the fresh water is found in snow and freshwater icebergs found in areas primarily in the Antarctic Circle. The annual global river flow of fresh water is 37.3 thousand cubic kilometers. In addition, a part of groundwater equal to 13 thousand cubic kilometers can be used. Unfortunately, most of the river flow in Russia, amounting to about 5,000 cubic kilometers, falls on the marginal and sparsely populated northern territories. In the absence of fresh water, salty surface or underground water is used, producing its desalination or hyperfiltration: it is passed under a large pressure drop through polymer membranes with microscopic holes that trap salt molecules. Both of these processes are very energy intensive, therefore, the proposal is of interest, which consists in using freshwater icebergs (or parts of them) as a source of fresh water, which for this purpose are towed along the water to shores that do not have fresh water, where they organize their melting. According to the preliminary calculations of the developers of this proposal, the production of fresh water will be about half as energy-intensive as compared to desalination and hyperfiltration. An important circumstance inherent in the aquatic environment is that infectious diseases are mainly transmitted through it (approximately 80% of all diseases). However, some of them, such as whooping cough, chickenpox, tuberculosis, are also transmitted through the air. To combat the spread of disease through aquatic environment The World Health Organization (WHO) has declared the current decade the decade of drinking water.

Fresh water. Fresh water resources exist thanks to the eternal water cycle. As a result of evaporation, a gigantic volume of water is formed, reaching 525 thousand km per year. (due to font problems, water volumes are indicated without cubic meters).

86% of this amount falls on the salty waters of the oceans and inland seas- Caspian. Aralsky and others; the rest evaporates on land, half of which is due to the transpiration of moisture by plants. Every year, a layer of water about 1250 mm thick evaporates. Part of it again falls with precipitation into the ocean, and part is carried by winds to land and here feeds rivers and lakes, glaciers and groundwater. The natural distiller feeds on the energy of the Sun and takes about 20% of this energy.

Only 2% of the hydrosphere is fresh water, but they are constantly renewed. The rate of renewal determines the resources available to mankind. Most of the fresh water - 85% - is concentrated in the ice of the polar zones and glaciers. The rate of water exchange here is less than in the ocean, and is 8000 years. Surface water on land is renewed about 500 times faster than in the ocean. Even faster, in about 10-12 days, the waters of the rivers are renewed. Fresh waters of the rivers have the greatest practical value for mankind.

Rivers have always been a source of fresh water. But in the modern era, they began to transport waste. Waste in the catchment area flows down the riverbeds into the seas and oceans. Most of the used river water is returned to rivers and reservoirs in the form of wastewater. So far, the growth of wastewater treatment plants has lagged behind the growth in water consumption. And at first glance, this is the root of evil. In fact, everything is much more serious. Even with the most advanced treatment, including biological treatment, all dissolved inorganic substances and up to 10% of organic pollutants remain in the treated wastewater. Such water can again become suitable for consumption only after repeated dilution with pure natural water. And here, for a person, the ratio of the absolute amount of wastewater, even if it is purified, and the water flow of rivers is important.

The global water balance has shown that 2,200 km of water per year is spent on all types of water use. Almost 20% of the world's fresh water resources are used to dilute wastewater. Calculations for the year 2000, assuming that water consumption rates will decrease and treatment will cover all wastewater, showed that 30-35 thousand km of fresh water will still be needed annually to dilute wastewater. This means that the resources of the total world river flow will be close to exhaustion, and in many parts of the world they have already been exhausted. After all, 1 km of treated waste water "spoils" 10 km of river water, and not treated - 3-5 times more. The amount of fresh water does not decrease, but its quality drops sharply, it becomes unsuitable for consumption.

Mankind will have to change the strategy of water use. Necessity forces us to isolate the anthropogenic water cycle from the natural one. In practice, this means a transition to a recirculating water supply, to a low-water or low-waste, and then to a "dry" or waste-free technology, accompanied by a sharp decrease in the volume of water consumption and treated wastewater.

Fresh water reserves are potentially large. However, in any part of the world, they can be depleted due to unsustainable water use or pollution. The number of such places is growing, covering entire geographic areas. The need for water is not met by 20% of the urban and 75% of the rural population of the world. The volume of water consumed depends on the region and standard of living and ranges from 3 to 700 liters per day per person. Water consumption by industry also depends on economic development of this area. For example, in Canada, the industry consumes 84% ​​of the total water intake, and in India - 1%. The most water-intensive industries are steel, chemical, petrochemical, pulp and paper, and food. They take almost 70% of all water used in industry. On average, industry consumes about 20% of all water consumed in the world. The main consumer of fresh water is agriculture: 70-80% of all fresh water is used for its needs. Irrigated agriculture occupies only 15-17% of the area of ​​agricultural land, and provides half of all production. Almost 70% of cotton crops in the world are supported by irrigation.

The total runoff of the rivers of the CIS (USSR) for the year is 4720 km. But water resources are distributed extremely unevenly. In the most populated regions, where up to 80% of industrial production lives and 90% of land suitable for agriculture is located, the share of water resources is only 20%. Many parts of the country are not sufficiently supplied with water. This is the south and southeast of the European part of the CIS, the Caspian lowland, south Western Siberia and Kazakhstan, and some other regions of Central Asia, the south of Transbaikalia, Central Yakutia. The northern regions of the CIS, the Baltic states, the mountainous regions of the Caucasus, Central Asia, the Sayan and Far East.

The flow of rivers varies depending on climate fluctuations. Human intervention in natural processes has already affected river runoff. AT agriculture most of the water does not return to the rivers, but is spent on evaporation and the formation of plant mass, since during photosynthesis hydrogen from water molecules passes into organic compounds. To regulate the flow of rivers, which is not uniform throughout the year, 1,500 reservoirs have been built (they regulate up to 9% of the total flow). To the drain of the rivers of the Far East, Siberia and the North of the European part of the country economic activity so far it hasn't had much of an effect on humans. However, in the most populated areas, it decreased by 8%, and near such rivers as the Terek, Don, Dniester and Ural, by 11-20%. The water runoff in the Volga, Syr Darya and Amu Darya has noticeably decreased. As a result, the flow of water to Sea of ​​Azov- by 23%, to Aral - by 33%. The level of the Aral fell by 12.5 m.

Limited and even scarce in many countries, fresh water supplies are being significantly reduced due to pollution. Usually pollutants are divided into several classes depending on their nature, chemical structure and origin.

Pollution of water bodies. Fresh water bodies are polluted mainly as a result of the discharge of wastewater into them from industrial enterprises and settlements. As a result of wastewater discharge, physical properties water (temperature rises, transparency decreases, color, tastes, odors appear); floating substances appear on the surface of the reservoir, and sediment forms at the bottom; changes chemical composition water (the content of organic and inorganic substances, toxic substances appear, the oxygen content decreases, the active reaction of the environment changes, etc.); the qualitative and quantitative bacterial composition changes, pathogenic bacteria appear. Polluted reservoirs become unsuitable for drinking, and often for technical water supply; lose their fishery importance, etc. The general conditions for the release of sewage of any category into surface water bodies are determined by their national economic significance and the nature of water use. After the release of wastewater, some deterioration in the quality of water in reservoirs is allowed, but this should not noticeably affect his life and the possibility of further use of the reservoir as a source of water supply, for cultural and sports events, and fisheries.

Monitoring of compliance with the conditions for the discharge of industrial wastewater into water bodies is carried out by sanitary and epidemiological stations and basin departments.

The water quality standards for reservoirs of domestic and drinking cultural and domestic water use establish the quality of water for reservoirs for two types of water use: the first type includes sections of reservoirs used as a source for centralized or non-centralized domestic and drinking water supply, as well as for water supply to enterprises Food Industry; to the second type - sections of reservoirs used for swimming, sports and recreation of the population, as well as those located within the boundaries of settlements.

The assignment of water bodies to one or another type of water use is carried out by the bodies of the State Sanitary Supervision, taking into account the prospects for the use of water bodies.

The water quality standards for water bodies given in the rules apply to sites located on flowing water bodies 1 km upstream of the nearest water use point, and on stagnant water bodies and reservoirs 1 km on both sides of the water use point.

Much attention is paid to the prevention and elimination of pollution of the coastal areas of the seas. Sea water quality standards, which must be ensured when discharging wastewater, refer to the water use area within the allotted boundaries and to sites at a distance of 300 m away from these boundaries. When using coastal areas of the seas as a receiver of industrial wastewater, the content of harmful substances in the sea should not exceed the MPC established for sanitary-toxicological, general sanitary and rganoleptic limiting indicators of harmfulness. At the same time, the requirements for the discharge of wastewater are differentiated in relation to the nature of water use. The sea is considered not as a source of water supply, but as a medical, health-improving, cultural and household factor.

Pollutants entering rivers, lakes, reservoirs and seas make significant changes to the established regime and disrupt the equilibrium state of aquatic ecological systems. As a result of the processes of transformation of substances polluting water bodies, occurring under the influence of natural factors, in water sources there is a complete or partial restoration of their original properties. In this case, secondary decomposition products of pollution can be formed that have a negative impact on water quality.

Self-purification of water in reservoirs is a set of interrelated hydrodynamic, physicochemical, microbiological and hydrobiological processes leading to the restoration of the original state of a water body.

Due to the fact that wastewater from industrial enterprises may contain specific contaminants, their discharge into the city drainage network is limited by a number of requirements. Industrial wastewater released into the drainage network should not: disrupt the operation of networks and structures; have a destructive effect on the material of pipes and elements of treatment facilities; contain more than 500 mg/l of suspended and floating substances; contain substances that can clog networks or deposit on pipe walls; contain combustible impurities and dissolved gaseous substances capable of forming explosive mixtures; contain harmful substances that prevent biological wastewater treatment or discharge into a reservoir; have a temperature above 40 °C.

Industrial wastewater that does not meet these requirements must be pre-treated and only then discharged into the city drainage network.

Table 1

World water reserves

No. p / p	Name of objects	Distribution area in million cubic km	Volume, thousand cubic meters km	Share in world reserve,
1	World Ocean	361,3	1338000	96,5
2	The groundwater	134,8	23400	1,7
3	including underground: fresh water	10530	0,76
4	soil moisture	82,0	16,5	0,001
5	Glaciers and permanent snows	16,2	24064	1,74
6	underground ice	21,0	300	0,022
7	lake water
8	fresh	1,24	91,0	0,007
9	salty	0,82	85.4	0,006
10	swamp water	2,68	11,5	0,0008
11	river water	148,2	2,1	0,0002
12	Water in the atmosphere	510,0	12,9	0,001
13	Water in organisms	1,1	0,0001
14	Total water supply	1385984,6	100,0
15	Total fresh water	35029,2	2,53

Conclusion.

Water is one of the main wealth on Earth. It is hard to imagine what would happen to our planet if fresh water disappeared. A person needs to drink about 1.7 liters of water per day. And about 20 times more daily is required for each of us for washing, cooking and so on. The threat of disappearance of fresh water exists. All living things suffer from water pollution, it is harmful to human health.

Water is a familiar and unusual substance. The famous Soviet scientist academician I.V. Petryanov called his scientifically popular book about water "The most extraordinary substance in the world." And Doctor of Biological Sciences B.F. Sergeev began his book "Entertaining Physiology" with a chapter on water - "The substance that created our planet."

Scientists are right: there is no substance on Earth more important for us than ordinary water, and at the same time there is no other substance of the same kind, in whose properties there would be as many contradictions and anomalies as in its properties.

Bibliographic list:

1. Korobkin V. I., Peredelsky L. V. Ecology. Tutorial for universities. - Rostov /on/Don. Phoenix, 2005.

2. Moiseev N. N. Interaction between nature and society: global problems// Bulletin of the Russian Academy of Sciences, 2004. T. 68. No. 2.

3. Environmental protection. Proc. allowance: V 2t / Ed. V. I. Danilov - Danilyan. - M.: Publishing house MNEPU, 2002.

4. Belov S. V. Environmental protection / S. V. Belov. – M. graduate School, 2006. - 319 p.

5. Derpgolts VF Water in the universe. - L .: "Nedra", 2000.

6. G. A. Krestov, From Crystal to Solution. - L .: Chemistry, 2001.

7. Khomchenko G.P. Chemistry for entering universities. - M., 2003

Water

Take a look at the world map. Most of all it has blue paint on it. And the blue color on the maps depicts water, which no one can ever do without, and there is nothing to replace it with.

In nature, the water cycle is constantly going on. From the surface of the seas, oceans, rivers and lakes, it evaporates, clouds form. They rain down, snow down, and return water to land and oceans again.

It was in the water that the first living beings arose. They were small single-celled protein lumps floating at the behest of the waves in the ocean. Gradually, over millions of years, they changed and improved. First, they gave rise to plant organisms, then forms arose that stood on the verge between plants and animals. And finally, the simplest animals appeared. Many more millions of years passed before, fighting for existence, part of the plants and animals "came out" on land and continued their development there.

Water is one of the most important substances for humans. His body, blood, brain, body tissues are more than half composed of water. And in some plants it is even more. Water - in the oceans and seas, rivers and lakes, underground and in the soil. On the high mountains, in the Arctic, Antarctica, water is in the form of snow and ice. This is solid water. Ice can be seen on our rivers and lakes when they freeze in winter. There is a lot of water in the atmosphere: these are clouds, fog, steam, rain, snow. On the surface of the land is not all the water available on Earth. In the depths of the soil there are underground rivers and lakes. Are you surprised that both solid ice and light, like gas, steam are also water? This is its property: it is liquid, solid and gaseous.

Water has another important property: it can easily dissolve many substances in itself. You have, of course, seen how table salt dissolves in soup. Water also dissolves various salts found in the earth's layers, and many other solids and even gases.

There is absolutely no pure water in nature. It can only be obtained in the laboratory. Such water is tasteless, it does not contain salts needed by a living organism. And in sea water there are too many different salts, so it is also not suitable for drinking. With a lack of water, the vital activity of organisms is severely disrupted. Only resting forms of life - spores, seeds - tolerate prolonged dehydration well. Plants in the absence of water wither and may die. Animals, if deprived of water, die quickly: for example, a well-fed dog can live without food for up to 100 days, and without water - less than 10. Loss of water is more dangerous for the body than starvation: a person can live without food for more than a month, without water - only only a few days. Organic and inorganic substances important for the life of the body are dissolved in water. A person's need for water, which he uses with food and drink, depending on the climate, is 3-6 liters per day. Water is a good friend and helper of man. She is - comfortable road: ships sail on the seas and oceans. That is why many cities arose on the banks of rivers.

Water conquers drought, revitalizes deserts, increases the yield of fields and orchards. She obediently rotates turbines at hydroelectric power plants. The water of mineral springs has a healing effect. Many of the springs are hot. And people use not only the healing properties of these waters, but also heat. In Kamchatka, where there are a lot of such sources, vegetables are grown in greenhouses at any time of the year. This is what an extraordinary substance is ordinary water - the beauty of nature, as the wonderful Russian writer S. T. Aksakov once said.

The total amount of water on Earth does not change. From the surface of the seas and oceans, rivers and lakes, water evaporates, and then returns to Earth in the form of rain or snow. But there is less and less clean water on Earth. Its lack is already being felt in many countries. However, this is not because water supplies are depleted. The threat of pollution loomed over the water. Plants and factories, power plants consume large amounts of water and at the same time pollute it with various waste products. Various toxic substances enter rivers and lakes with wastewater from enterprises. Life perishes in the water. Fish, crayfish, plants - all living things die in such water. Decaying waters poison the air and become sources of serious diseases. The river is sick, its waters cannot be used by man. Water must be saved! This must be understood and remembered by everyone. Conserving water means protecting life, health, and the beauty of the surrounding nature. Our country has adopted a number of laws aimed at protecting water. Their implementation is monitored by the state authorities. This made it possible to reduce the risk of pollution on many rivers and improve the sanitary condition of cities and towns. But the problem of water protection is still acute.

Bibliography

For the preparation of this work, materials from the site http://www.5.km.ru/

Water on our planet is in three states- liquid, solid (ice, snow) and gaseous (steam). Currently, water occupies 3/4.

Water forms the water shell of our planet - the hydrosphere.

Hydrosphere (from Greek words"hydro" - water, "sphere" - a ball) includes three main components: the oceans, land waters and water in the atmosphere. All parts of the hydrosphere are interconnected by the process of the water cycle in nature already known to you.

1. Explain how water from the continents enters the oceans.
2. How does water get into the atmosphere?
3. How does water get back to land?

The oceans account for over 96% of all water on our planet.

Continents and islands divide the World Ocean into separate oceans: Pacific, Atlantic, Indian,.

AT last years maps highlight the Southern Ocean - the body of water surrounding Antarctica. The largest in area - Pacific Ocean, the smallest is the Arctic.

The parts of the oceans that protrude into the land and differ in the properties of their waters are called seas. There are a lot of them. The largest seas of the planet are the Philippine, Arabian, Coral.

Water in natural conditions contains various substances dissolved in it. 1 liter of ocean water contains on average 35 g of salt (most of all table salt), which gives it a salty taste, makes it unsuitable for drinking and use in industry and agriculture.

Rivers, lakes, swamps, glaciers and underground waters are land waters. Most of the land's waters are fresh, but salty ones are also found among lakes and groundwater.

You know what a huge role rivers, lakes, swamps play in nature and people's lives. But here's what is surprising: in the total amount of water on Earth, their share is very small - only 0.02%.

Much more water is enclosed in glaciers - about 2%. Do not confuse them with the ice that forms when water freezes. occur where more falls than has time to melt. Gradually, the snow accumulates, compacts and turns into ice. Glaciers cover about 1/10 of the land. They are located primarily on the mainland of Antarctica and the island of Greenland, which are covered with huge ice shells. Blocks of ice that break off along their shores form floating mountains - icebergs.

Some of them reach enormous sizes. Large areas are occupied by glaciers in the mountains, especially in such high places as the Himalayas, the Pamirs, and the Tien Shan.

Glaciers can be called pantries of fresh water. So far, it has hardly been used, but scientists have long been developing projects to transport icebergs to arid regions in order to provide drinking water local residents.

They also make up about 2% of all water on Earth. They are located in the upper part of the earth's crust.

These waters can be salty and fresh, cold, warm and hot. Often they are saturated with substances useful for human health and are medicinal (mineral waters).

In many places, for example, along the banks of rivers, in ravines, groundwater comes to the surface, forming springs (they are also called springs and springs).

Groundwater reserves are replenished due to atmospheric precipitation, which seeps through some of the rocks that make up earth's surface. Thus, groundwater is involved in nature.

Water in the atmosphere

Contains water vapor, water droplets and ice crystals. Together they make up fractions of a percent of the total amount of water on Earth. But without them, the water cycle on our planet would be impossible.

1. What is the hydrosphere? List its constituent parts.
2. What oceans form the World Ocean of our planet?
3. What makes up land water?
4. How are glaciers formed and where are they located?
5. What is the role of groundwater?
6. What is water in the atmosphere?
7. What is the difference between river, lake and ?
8. What is the danger of an iceberg?
9. Are there salt water bodies on our planet other than seas and oceans?

The water shell of the Earth is called the hydrosphere. It consists of the oceans, land waters and water in the atmosphere. All parts of the hydrosphere are interconnected by the process of the water cycle in nature. The oceans account for over 96% of the world's water. It is divided into separate oceans. The parts of the oceans that jut out into the land are called seas. Land waters include rivers, lakes, swamps, glaciers, groundwater. The atmosphere contains water vapor, water droplets and ice crystals.

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