Water - this is the most amazing substance on Earth.That's it, we owe our lives, as it is involved in all processes of life.Water has the most unusual properties, and not all of them, scientists were able to explain.For example, it turned out that she has a memory, and can respond to different words.The most well-known property of water - that's what it is - the only substance that can be located in all three states of aggregation.Liquid - is, in fact, water, solid - it's ice.The gaseous state of water we can see constantly in the form of vapor, fog or clouds.The average person does not think that this is all water, he used to call this word only liquid.Many do not even know the name of the gaseous state of water.But this feature of its support life on Earth.
value of water
This wonderful moisture is about 70% of the Earth's surface.In addition, it can be found at great depth - deep in the Earth's crust and high in the atmosphere.The entire mass of water in the form of liquid, ice and steam is called the hydrosphere.It is vital to all life on Earth.It was under the influence of water formed by the climate and weather around the world.And the existence of life depends on its ability to move from one state to another.This feature provides its water cycle.Of particular importance is the water in the gaseous state.This feature helps it to move large masses of water over long distances.Scientists estimate that the sun evaporates the minute with the Earth's surface a billion tons of water, which is in the form of clouds is transferred to another place, and then to rain.
gaseous state of water
water features is that its molecules are capable of temperature variation changing nature of the relationship with each other.Its basic properties are not changed.If you heat water, its molecules begin to move faster.Those who come into contact with air, and break its ties with its molecules are mixed.The water in the gaseous state retains all its qualities, but also takes on the properties of the gas.Its particles are at a great distance from each other and intensely moving.Most often, this condition is called water vapor.This colorless, transparent gas, which under certain conditions again become in water.It is widely distributed in the world, but most of it is not visible.Examples of the water in the gaseous state - a cloud or fog water vapor formed during boiling of the liquid.Furthermore, it is always in the air composition.Scientists have observed that when moistened breathing becomes easier.
What is steam?
In most cases the water passes into the gaseous state when the temperature changes.Conventional steam which all the mark is formed during boiling.It is off-white hot cloud we call steam.When the liquid by heating reaches the boiling point at normal pressure and it occurs at 100 °, its molecules begin to evaporate rapidly.Getting on colder objects, they are condensed into water droplets.If a large amount of liquid is heated, the air saturated steam is formed.This state, when the gas and water coexist, because the rate of evaporation and condensation of the same.In the case where much air is present in the vapor, say about its humidity.When the air temperature is lowered so intense moisture condenses as droplets of dew or fog.But mist a little special conditions of temperature and humidity.It is necessary that the air was a certain amount of dust particles around which moisture condenses.Therefore, in the mists of the cities because of the dust produced more often.
Moving water from one state to another
process steam generation is called vaporization.He watches every woman cooking.But there is a reverse process, when the gas is converted back into the water, settling on the subject in the form of tiny droplets.This is called condensation.How, then, most often occurs vaporization?Under natural conditions, this process is called evaporation.Water evaporates constantly under the influence of solar heat or wind.Artificially steam generation can be called up with the boiling water.
Evaporation
This is a process where a gaseous state of water.It may be natural or accelerated by a variety of devices.It evaporates water constantly.It's her property people have long used to dry the laundry, dishes, wood or grain.Any wet object slowly dries through evaporation of moisture from its surface.The water molecules in its movement one after another detach and mix with the air molecules.By observing people learned how to accelerate the process.To do this, even created various devices and appliances.
How to speed up the evaporation?
1. People have noticed that the faster this process takes place at high temperature.For example, the summer wet road dries instantly, which is not true about the fall.Therefore, dried objects people in warmer areas and recently created a special heated dryers.And in cold weather, too, the evaporation is happening, but very slowly.This property is used to dry
valuable ancient books and manuscripts, placing them in special freezers.
2. Evaporation is faster if the area of contact with air is large, such as a plate of water disappears faster than banks.This property is used in the drying of fruits and vegetables, slicing them into thin slices.
3. More people have noticed that the items dry quickly under the influence of wind.This is because the flow of air entrained water molecules, and they are not able to condense again on this subject.This feature was used to create the dryer and air hand dryers.
Properties of water in the gaseous state
Steam mostly invisible.But at high temperatures, when water evaporates immediately much it can be seen as a white cloud.The same thing happens in cold air, when water molecules are condensed as tiny droplets, which we observe.
water in gas form may be dissolved in the air.Then we say that it has increased humidity.There is a maximum possible concentration of water vapor, which is called the "dew point".Above this limit, it condenses into a mist or cloud of droplets of dew.
water molecules in the gaseous state are moving very fast, taking a large amount.This is especially noticeable at high temperature.So you can see how at boiling kettle jumping from cover.The same property leads to the fact that the combustion of wood crackling can be heard.This evaporating water breaks the fibers of the wood.
Water vapor is resilient.He is able to expand and contract with changes in temperature.
Application properties of steam
All these properties have long studied people and is used for domestic and industrial needs.
- first gaseous state of water used in steam engines.For many years it was the only opportunity to drive the trucks and machines in the industry.Steam turbines are used now and in vehicles petrol engine has long been supplanted steam.And now the locomotive can be seen only in museums.
- widespread and long-pairs used in cooking.Preparation of meat or fish for a couple makes them gentle and beneficial to all.
- Hot steam is also used for heating homes and in industrial processes.Steam heating is very efficient and quickly gained popularity among the population.
- gaseous state of water used in fire extinguishers is now a special design that are used for extinguishing oil and other flammable liquids.The heated steam blocks access of air to the hearth fire, stopping burning.
- In recent years, use of gaseous water to care for clothing.Special steamers not only smooth out the delicate things, but also will bring some spots.
- Very efficient use of steam for sterilization of medical tools and objects.
When water vapor is harmful?
there in the world and places where water is in the gaseous state is almost always.This is the valley of geysers and active volcanoes in the vicinity.There is a person in such an atmosphere is not possible.There's hard to breathe, and the humidity prevents the evaporation of moisture from the skin, which can lead to overheating.You can also get burned so much steam that is produced during boiling water.A fog can reduce visibility, leading to accidents.But in all other cases, the property of water to pass into the gaseous state is used for the good of the person himself.
