Water

Water is the most abundant liquid on the planet, and its formula, H2O, is the most famous in the world.

Water is one of the most mysterious compounds on Earth. At all times, people believed in its superpowers: in ancient times they talked about "dead" and "living" water, today you can increasingly hear about the unusual properties of a structured liquid.

Water in terms of chemistry

H2O is an incredibly simple formula, but there is an important and mysterious substance behind it. And even chemistry, as a science, owes its existence to liquids - the first experiments were carried out on aqueous solutions. Despite this, the water has not yet been fully studied.

Hydrogen oxide, as chemists call this substance, consists of two hydrogen atoms and one oxygen. When combined, these three elements create an incredibly strong bond, which is not so easy to break. The whole secret is that hydrogen ions are so small that they can penetrate the shell of the oxygen atom of a neighboring molecule. This forms a strong connection that combines 4 elements. The strength of this connection protects the structure of water from destruction for millions of years.

Substance has many names. For people who are not associated with scientific activities, it's just water. And scientists call the transparent liquid hydrogen oxide or hydroxide, oxidane, dihydrogen monoxide, dihydromonoxide, and even hydroxyl acid.

From the point of view of chemistry, water is considered as an ampholyte - a substance that simultaneously has the properties of an acid and a base. This is one of the unique properties of the liquid.

Dihydrogen is a chemically active substance, a solvent of other elements - organic and inorganic. In the school curriculum, they study that H2O reacts with active metals (for example, calcium, potassium, sodium ), halogens, such as fluorine or chlorine, as well as with salts, acids and many other compounds. In addition, when heated, it reacts with some other elements ( iron, magnesium, coal, methane, alkyl halides).

When water is not liquid

A colorless substance without taste and smell, depending on the conditions, can be in a liquid, vapor or solid state. Only water is capable of such reincarnations - no other substance can change in such a way. These features are possible due to the unique type of bonds within the molecule.

100 degrees is not always the boiling point

It is well known that when the thermometer shows 0 °C, water freezes, and at 100 °C it boils, turns into steam. But this law is applicable only under the condition of a certain atmospheric pressure - 760 mm Hg. Art. (1 atmosphere). In proportion to the decrease in pressure, the melting point of ice increases, and the boiling point, on the contrary, decreases.

When atmospheric pressure drops to a certain level, water loses its ability to remain liquid: with temperature fluctuations, ice immediately turns into steam and vice versa.

If the pressure is increased, another interesting effect can be achieved: melting ice requires a temperature above room temperature. And if in the formula H2O instead of oxygen there were elements adjacent to the periodic table (for example, sulfur or selenium), then the substance would boil already at 80 ° C.

In physics there is such a thing as the triple point of water. This term refers to the moment when a liquid exists simultaneously in three states: solid, liquid and gaseous. Scientists say that to achieve this effect, a pressure of 0.006 atmospheres and a temperature of 0.001 ° C are needed.

And another amazing ability. If there are no dissolved gases in the composition of water, it will not turn into ice even at 70 degrees below zero and will not boil even at +150.

Volumes outside the rules

Density is another of the physical parameters that are characteristic of all substances on the planet. Water is no exception. But here, too, the liquid has its own characteristics that go beyond the laws of physics.

Scientists have proven that the density of any substance depends on temperature and volume. As the temperature increases, the volume increases and the density decreases. But this rule stops working with water, the temperature of which is from 0 to 4 ° C - with an increase in temperature, the volume, on the contrary, decreases. Due to the fact that the density of ice is lower than the liquid form, water bodies always begin to freeze from above, not from below. And the ice crust formed on top prevents the rest of the liquid from freezing.

And a few more unique features

Hydrogen oxide under normal conditions (at certain temperatures and pressures) is a colorless liquid, odorless and tasteless. But it turns out that only water can maintain fluidity in such circumstances. In a similar situation, other similar hydrogen compounds appear to a person in the form of gases. Such qualities are again due to specific bonds within the H2O molecule.

If the glass is overturned, the contents do not scatter around, do not crumble, but form a puddle with clearly defined edges. This is due to the specifics of the water molecule - the substance retains viscosity and high surface tension (according to this indicator, dihydrogen monoxide loses only to mercury).

Hydrogen oxide is one of the best solvent substances. Avoiding scientific terminology, this process can be described something like this. Water molecules take each solute molecule into a ring. But not randomly, but according to a certain pattern: ions with a positive charge attract oxygen atoms to themselves, and negatively charged particles attract hydrogen. By the same principle, water fills the space in the cells of all living organisms.

Since water almost always contains some kind of salt, that is, there are ions with a positive and negative charge, it also has the ability to conduct electricity. At the same time, pure water, which does not contain impurities of other ions, on the contrary, is an ideal insulator.

Where did H2O come from on the planet?

Water is vital to the survival of mankind. Today we know a lot about this substance, except for the very first question: where did it come from on the planet.

Everyone remembers a picture from high school that depicts the water cycle in nature. The liquid evaporates from water bodies, condenses, forms clouds and returns to the earth in the form of rain. All this is true, but the school picture in no way explains where the very first water came from....

It is believed that the history of the appearance of water on our planet has about 13.8 billion years before the Big Bang. Astronomers believe that comets and asteroids that attacked our planet for millions of years carried the liquid to Earth. But whether it all happened in reality, today it is impossible to answer - scientific disputes continue.

More recently, researchers from the University of Hawaii, analyzing the composition of the rocks on the island of Baffin Island (Canada), came to an unexpected conclusion. They put forward a new theory - about the so-called "native" water on Earth. The rocks on the island were formed directly from the mantle, without any influence from the earth's crust. And in their composition, the researchers found glass crystals, and in them - droplets of water, whose chemical composition turned out to be identical to the formula of the rest of hydrogen oxide.

Hawaiian scientists do not undertake to refute the theory of asteroids and comets, but urge the scientific world to take a fresh look at the possible sources of the first water on the planet. Perhaps, when the Earth was still young, it was fed by moisture from several points?..

Moisture on the planet

1,500 million cubic kilometers of H2O. This value is stable and the amount of liquid on the planet has not changed for millions of years.

Part of it is superficial. These are exactly the reserves that are visible even from outer space, the liquid thanks to which our planet was called the Blue Ball.

The second part of planetary moisture is underground reserves. Most often they are a kind of giant vessels containing water under high pressure. The first underground "reservoirs" are opened at a depth of only a few meters. It is these water reserves that serve as the basis for domestic wells. Given that the top layer of the earth is quite loose, they are often dirty and not suitable for drinking.

But even in prehistoric times, people knew how to purify water, making it suitable for use. For example, the ancient Egyptians were the first on the planet to describe how to purify water. This ancient instruction dates back to around 1500 BC. To make the liquid safe for consumption, the ancient inhabitants of the banks of the Nile most often boiled it, heated it in the sun, or immersed a piece of red-hot iron in water. And to make it transparent, they passed a boiling liquid through a layer of sand and gravel. Today, mankind resorts to other cleaning methods, using the knowledge of chemistry and physics.

Almost 70% of the Earth's surface is covered with water. But 97% of all moisture on the planet is a salty substance, saturated with various minerals and chemical compounds. Theoretically, a person can use it for drinking after cleaning from impurities. But in practice it is quite difficult and extremely expensive.

Approximately 2% of the water supply is fresh liquid stored in glaciers at the North and South Poles. They could become a means of quenching thirst, if not for one "but" - a distant location from the habitat of people. A little more than 1.5% of all reserves are groundwater, and 0.001% of moisture is stored in the clouds. And only less than 1% of H2O reserves are actually available to people. But this is not all the water resources of the Earth. More than 6 thousand km3 liquid is found in all living organisms on the planet. And these are plants, animals and you and me. After all, we remember that a person is 60-70% H2O.

If we calculate the percentage of all water on the planet, it turns out that:

  • 97.54% are oceans;
  • 1.81% - glaciers;
  • 0.63% - groundwater;
  • 0.009% - rivers and lakes;
  • 0.007% - salt water on the continents;
  • 0.001% - water in the atmosphere.

Types of terrestrial water

Water on Earth is represented in salt form (more than 97%), fresh (2.5%) and in the form of brines (liquid with an admixture of salts, otrutochemicals, organic compounds).

But this is not the only classification of liquid. Paying attention to the content of calcium and magnesium in its composition, soft and hard water are distinguished. Given the nature of the hydrogen isotope, it is light, heavy and superheavy.

In addition, some classifications distinguish a thawed substance, the structure of which, as is sometimes convinced, is identical to the protoplasm of the cells of our body and has useful properties.

Water and…climate

It is known that hydrogen oxide is able to give off heat, almost without reducing its own temperature. This is one of the factors on which the climate on the planet depends.

Landforms are also formed by water. Being the second most mobile (after air) substance on the planet, dihydrogen monoxide is able to travel long distances, changing the surface of the soil on its way.

…Space

But the Earth is not the only place where water “habitates”. This substance is often found in space, though more often in the form of ice or steam. And it is this fact that allows some scientists to suggest that life on other planets is also possible.

Space researchers believe that some comets are 50% water (in the form of ice). And in 2009, NASA employees received reliable evidence that there is ice on the Moon, and in a fairly large amount. In addition, there is water-ice on the satellites of Saturn and Jupiter (Europa, Tethys, Enceladus, Ganymede), as part of asteroids. It is also assumed that H2O is also present on trans-Neptunian objects.

The atmosphere of almost all the planets of the solar system (including the Sun) contains water in the form of steam. Most of these reserves are in the atmosphere of Mercury - approximately 3.4%. For comparison: the earth's atmosphere over the tropics contains about 3-4% of steam, and in the Antarctic - only 2x10−5%.

But the water reserves of the Cosmos are not limited to this. It is believed that water in liquid form is a common occurrence on some satellites of the planets. So far, scientists are pinning their greatest hopes on Jupiter's moon Europa.

... a person

It is generally accepted that a person is 2/3 water. But in fact, this indicator is not static, and the water percentage in our body composition fluctuates throughout life.

Most of the moisture is in the human embryo. The embryo of the future human is approximately 97% water. A little less, within 92% of the fluid, is contained in the body of a newborn. Teenagers are already 80% water, and adults are “flooded” by 70-75%.

The least H2O in the body of the elderly is only 60%. Isn't that why, over the years, a person loses vitality and starts to get sick?

Perhaps, water is the only substance, the absence of which the body reacts very quickly and immediately with serious consequences. It is believed that without food a person can survive for several weeks. Deficiency of vitamins, micro- and macronutrients will cause negative consequences also after some time. But it is enough to give up water for just a few days, so that the body makes it clear: this is a disaster.

We begin to lose moisture reserves already at the first manifestations of thirst. It is enough to lose only 5% of the liquid in order to have difficulties with swallowing syndrome, hallucinations and fainting begin, and hearing and vision are impaired. If the water balance is not restored in time, a fatal outcome is possible.

Functions of water in the body:

  • removes toxins, slags, salts and waste products;
  • transports beneficial substances to all organs;
  • promotes muscle contraction;
  • acts as a lubricant for the joints;
  • regulates hematopoiesis, blood pressure;
  • activates the brain;
  • accelerates metabolic processes;
  • maintains a stable body temperature;
  • protects organs from damage;
  • adds strength and energy.

Human benefits

Water is the main component of all tissues in the human body.

The concentration of fluid in each organ is different. The largest reserves of moisture are concentrated in the eyeball (which is almost 99% water), and the lowest - in the enamel of the teeth (only 0.2%). There is also a high concentration of water in the brain (almost 70%), so without the liquid the robotic organ would be impossible.

Dihydrogen monoxide is all around us. And more than half of the human body is H2O. All biochemical processes within us also require water. So, how does hydrogen oxide affect the functioning of the body?

The role of water:

  1. Proper digestion.

Correct water balance promotes physiological digestion. Water helps to quickly and easily get rid of waste products, reduces the burden on the kidneys and liver during body cleansing, and prevents constipation.

  1. Health of the cardiovascular system.

There is an association between the amount of drinking water consumed and the risk of coronary heart disease. The risk of heart disease is much lower for those who prefer clean drinking water instead of sugary juices and sodas.

  1. Muscle strength.

Sweating in the gym causes the muscles to lose moisture, and when there is not enough water, the muscles tire more quickly. Therefore, to maintain energy during long workouts, it is important to restore fluid reserves.

  1. Freshness of the skin.

Acne and skin inflammation are often caused by toxins. Drinking more water will help to quickly cleanse the body. Also, the correct balance of moisture will protect the skin from premature aging, drying and wrinkles.

  1. Cancer prevention theory.

Recent research has led scientists to come up with an interesting theory. According to them, the development of bladder cancer largely depends on the level of water in the body: the higher the moisture index in the body, the lower the risk of getting sick. Scientists explain this theory by the fact that frequent urination allows you to quickly (and in larger quantities) remove carcinogens from the body, preventing their accumulation in the bladder. According to the same principle, the researchers believe, you can protect yourself from breast and colon cancer.

  1. Benefits for the kidneys.

Kidneys eliminate toxins, help control body fluid balance and blood pressure. The only way to keep the body functioning properly is to consume enough fluids.

  1. Protection for cartilage and joints.

Moisture keeps the cartilage around the joints flexible and does not dry out, and for the joints themselves, water is part of the lubricant. By the way, periarticular cartilage is almost 85% dihydrogen monoxide, which is why maintaining a healthy level of moisture is so important.

  1. Significance for the brain.

Dehydration has an extremely negative effect on the tissues of the brain, which, without moisture, begins to shrink. Without maintaining proper water balance, it is more difficult for him to perform his functions, especially during exams or responsible affairs.

  1. Protection against respiratory viral infection.

An experiment conducted with the participation of 400 people showed that in order to protect yourself from infections and respiratory diseases during an epidemic, you need to follow the rules of personal hygiene and regularly gargle with ordinary clean water. People who took part in the experiment were less likely to get sick, and the disease proceeded in a milder form, without complications.

  1. Stamina and alertness are under control.

Dehydration always causes weakness and fatigue. Have you noticed that you started to get tired more often, and your strength is leaving you? Calculate how much water you drink per day. Perhaps the cause of fatigue is a lack of fluid. If you need to remain vigilant for a long time, you should make sure that you always have a bottle of still water on hand. Dehydration leads to a deterioration in concentration, and also reduces concentration, impairs motor skills and memory.

  1. Remedy for depression.

Another interesting study showed that mood is directly related to the amount of water in the body. The higher the percentage of dehydration, the worse the mood. It is also interesting that, according to researchers, water is also a remedy for depression. After taking a warm shower, the body activates the production of oxytocin, a hormone that causes relaxation.

  1. This healing sound of the surf…

Many people know that you can look at fire and water forever. True, one must not only look at the water, but also listen to its sounds, which, according to researchers, have a therapeutic effect. Unpleasant noises of public transport, construction tools and screams lead to an increase in blood pressure, speed up the pulse, causing the release of stress hormones. And the sounds of water, on the contrary, are among the most pleasant for a person. They are able to soothe and have a beneficial effect on the entire body.

There is also an opinion that people living on the coast have better health, and water aerobics brings more benefits, in particular for the cardiovascular system, than classes on land.

How much moisture does a person need

How much water should one drink daily? There is no clear answer to this seemingly simple question. Over the years, scientists have done a lot of research and every time they have come up with different numbers. In fact, there is no single answer. It all depends on the age, gender, habitat and type of human activity.

Coastal people get extra moisture from the air, so they can afford to drink a little less liquid than others. But residents of hot countries, on the contrary, should control their water balance as carefully as possible, as they are more prone to dehydration.

Drinking less liquid than required by the body leads to serious disturbances in the functioning of systems and organs. But excess is also dangerous to health. So who and how much water is supposed to?

Under normal circumstances, the amount of moisture in the body is controlled by thirst and urination. And this is a normal water cycle. It should not be forgotten that thirst can be a sign of certain diseases, in particular diabetes mellitus ​​. Therefore, if the desire to drink does not disappear for a long time, you should immediately consult a doctor.

In 2010, at their regular congress, nutritionists of Europe proposed that the minimum water consumption standards be:

  • 2 liters for men;
  • 1.6 L for women.

But these are only approximate figures that do not take into account the lifestyle and physical activity of a person.

In addition, there is a formula by which you can calculate a more accurate daily allowance based on body weight. To do this, it is enough to know that for 1 kg of weight there should be 30 ml of water daily.

Who has more?

However, there are situations when the body needs to increase fluid intake:

  • constipation (increasing fluid intake will help to cope with problem);
  • physical activity in the heat;
  • cystitis (helps expel pathogens).

The body's need for water increases during breastfeeding and in old age.

Hot weather, excessive sweating, indigestion, accompanied by vomiting and diarrhea, are also reasons to add a few more glasses of water to the usual daily allowance.

An extra bottle of drinking water is also worth considering for people who consume excessive salt. After too salty food, you always want to drink. Thus, the body signals the need for additional water, as excess salt changes the composition of the blood.

Daily fluid intake also depends on weather conditions. Outside the window high temperature and low humidity? These are ideal conditions for overheating the body. To protect against this, the body begins to sweat intensely. Therefore, in order to avoid dehydration, it is important to regularly restore the moisture reserves lost by the body.

Signs of dehydration

Feeling thirsty and dark urine with a pungent odor are clear signs of dehydration.

Other symptoms include:

But the most serious consequence of moisture deficiency is blood clotting. In such a consistency, it is not able to effectively perform its functions: the organs do not receive oxygen in the right amount, and the metabolic products do not leave the body, poisoning it.

All mucous membranes suffer from lack of fluid in the body. Not getting the required amount of moisture, they dry out and begin to crack. Dry skin, acne, brittle hair, tongue coating, bad breath, nervousness, distraction, and migraines are also outward signs of dehydration.

People from the extreme age groups, i.e. children and the elderly, are more at risk of dehydration. If the baby began to breathe faster, became sleepy and lethargic, and the number of wet diapers per day decreased significantly, this may be a signal of dehydration. The lack of moisture in the elderly body usually causes confusion in the mind.

It is important to remember that diarrhea, vomiting, and profuse sweating during fever can cause rapid dehydration. According to studies, the loss of approximately 1.5% of moisture causes mood swings, decreased concentration and headaches. And dehydration by 2-3% adversely affects the functioning of the brain.

In addition, dehydration can cause diseases such as:

  • obesity;
  • arthritis;
  • gastritis and constipation;
  • gallstones.

Dangerous dihydrogen monoxide

The danger of drinking too much water depends on the degree of excess and the state of health. A person whose kidneys are functioning properly is able to quickly get rid of excess moisture. However, stable hyperhydration (excessive saturation of the body with water) is dangerous by washing out useful salts. In particular, some athletes (particularly marathon runners) who drink too much water are severely sodium deficient. But for people with kidney pathologies or heart problems, excess moisture in the body can become a serious problem - it can cause swelling of the feet, ankles, and face.

An excess of H2O in the body can be indicated by overweight, edema, profuse sweating, and high blood pressure. In especially severe cases, disturbances in the work of the heart and lungs are possible.

Proper water balance is an important aspect for human health and life. For this reason, nature has endowed us with mechanisms to regulate the level of moisture in the body. When the volume of water falls below the allowable, we feel thirsty.

What determines the percentage of H2O in the body

The percentage of moisture in the body is an individual indicator for each person.

Gender, age, place of residence, lifestyle and body structure affect the amount of fluid. By the way, in obese people due to adipose tissue, the percentage of fluid in the body is higher than in people with normal or underweight.

But not only physiology determines the water content. The nature of the food also affects it. Alcohol, coffee, smoking and meat consumption in large quantities accelerate the removal of moisture. Sodas, which contain chemicals that accelerate dehydration, can also cause water imbalance.

It is important to take this knowledge into account when drawing up an individual water consumption program. But ordinary table salt will help retain moisture in the body. With this in mind, it is easy to prevent dehydration in hot weather or after eating disorders.

A mixture of 1.5 g salt, 2.5 g vitamin C and 5 g glucose diluted in half a liter of water will help prevent moisture loss. This recipe is actively used by travelers in conditions of lack of liquid to drink.

Liquid absorption

Only pure water, without harmful impurities, is considered useful for humans. It is important to avoid the so-called "heavy" substance, which is an isotope of H2O. Its main difference is in the structure of the molecule, and this subsequently complicates the course of all biochemical processes in the body.

Many researchers recommend giving preference to the “light” version of water - melted water. It is believed that this liquid can have a beneficial effect on the cardiovascular system, metabolic processes and tissue regeneration.

Also, the process of water digestibility directly depends on the state of health (it worsens with dehydration and in old age). In especially severe cases, the water balance of the body is restored with physiological or Ringer-Locke solution, administered intravenously.

Water will save you from extra pounds

Lovers of weight loss diets most likely know that water helps fight excessive appetite. Got hungry? It's easy to fool the body. To do this, it is enough to drink a glass of warm water - the stomach will stretch, signals of saturation will go to the brain.

In addition, according to studies, 500 ml of liquid can temporarily (over 90 minutes) increase metabolism by 25-30%. And drinking 2 liters of water a day, according to scientists, increases energy expenditure by about 96 calories. In this case, it is better to give preference to cold water - the body will spend additional calories on warming the liquid.

Other studies have shown that drinking a glass of water about half an hour before a meal can also reduce calorie intake. This technique is especially effective in the elderly. Dieters need to drink 2 glasses of water before meals to lose 44% more excess weight in 12 weeks.

But the influence of water on body weight is not limited to this. H2O deficiency, on the contrary, can cause obesity. And the thing is that a thirsty body, being in a state of stress, sends signals to the brain... about hunger. A person begins to eat, and excess calories are deposited in the form of subcutaneous fat.

To drink or not to drink - that is the question...

First, second and compote - this lunch set has been known to everyone since kindergarten. In this diet, everything seems to be correct, except for the order in which the products are taken. Usually we leave compote, tea or water at the end of the meal. And this is the whole mistake. If the liquid drunk before a meal normalizes physiological processes in the body and helps to lower blood cholesterol, then all drinks after a meal are only harmful.

Doctors categorically oppose this practice because water dilutes the gastric juices, slowing down the digestion process. Therefore, any drink should be consumed no earlier than one and a half to two hours after eating. But eating dry food is also not worth it. Sandwiches, pastries and other dry foods are best eaten with drinks or clean water.

But you can do more than just drink water…

The recommendation of many nutritionists is to consume at least 8 glasses of fluid per day. For some, this may seem too complicated. But who said that you have to drink the whole norm? Some of it can be... eaten.

Meat and fish, although they do not contain as much water as plant foods, can still serve as a source of H2O. For example, flounder is 79% water, chicken meat is 69%, and ground beef contains 63% moisture. As for chicken eggs, they are 75% water. Relatively high levels of dihydrogen monoxide are found in yogurt (about 89%), milk (87%) and ice cream (61%). But in hard cheeses, the maximum limit is 40% moisture.

Top 15 most watery foods:

  • cucumber (96.7% water content);
  • lettuce (96.6%);
  • celery (95.4%);
  • radish (95.3%);
  • tomatoes (94.5%);
  • green pepper (93.9%) (in red and yellow varieties, the water content is 92%);
  • cauliflower (92.1%)
  • watermelon (91.5%);
  • spinach (91.4%);
  • carom (91.4%);
  • strawberries (91%);
  • broccoli (90.7%);
  • grapefruit (90.5%);
  • young carrots (90.4%);
  • melon (90.2%).

Interesting facts about water:

  1. According to UN forecasts, 2/3 of the world's population will face water shortage water by 2025.
  2. Drinking too much dihydrogen monoxide can cause death (so-called water intoxication).
  3. Water is the most common substance on the planet.
  4. If all the world's supply of H2O were contained in a 4 liter jug, the amount of liquid suitable for human use would be 1 tablespoon.
  5. Under certain conditions, hot water can freeze faster than cold water (Mpemba Effect).
  6. Every day a person exhales a little more than a glass of water.
  7. Water expands by 9% when it freezes.
  8. The highest percentage of H2O is in cucumbers and in the body of a jellyfish (about 95%).
  9. Hydrogen oxide in liquid form reflects 5% of the sun's rays, while snow reflects more than 85%.
  10. Sea water freezes at about minus 2 degrees Celsius.
  11. If the Earth's surface were absolutely flat, the World Ocean would rise 3 km above it.
  12. Water reserves in the mantle of our planet are 10 times greater than the reserves of the World Ocean.
  13. An eighth of the land would be under water if all the glaciers melted.

And this, perhaps, is far from all that water can surprise us with. Scientists will continue to make amazing discoveries about this extraordinary substance. In the meantime, humanity, like hundreds of years ago, enjoys the sight of sea waves and drops of morning dew and, with bated breath, trembles before the water element during floods and thunderstorms, admiring the beauty and power of water.