The world around is an interconnected organism in which all processes and phenomena of animate and inanimate nature occur for a reason. It is proved by scientists that even minor human interventions bring enormous changes. Despite this, people forget that they are also an integral part of the world. In this regard, changes are occurring in humanity as a whole.
All about life processes and natural phenomena begin to be taught to children already at school, which is very important for their further understanding of what is happening around. As you know, the theme "Evaporation" (8th grade) is studied precisely in the framework of the secondary school program, when students are ready to reflect on problems.
How does evaporation occur?
Everyone knows what evaporation is. This is the phenomenon of the transformation of substances of different consistencies into a state of vapor or gas. It is known that this process occurs at the appropriate temperature.
Usually, under natural conditions, many substances (both solid and liquid) practically do not evaporate or do it very slowly. But there are also such samples, for example, camphor and most liquids, which, under normal conditions, evaporate very quickly. Therefore, they were called volatile. This process can be noticed with the help of smell, because many bodies are toxic.
The evaporation of a liquid (water, alcohol) can be traced by observing it for some time. Then begins a decrease in the volume of this substance.
The basis of life on earth
As you know, water is an integral part of the existence of the world. Without it, no being is possible, since all living things are 75% water.
This is a special compound whose properties are exceptional. And only thanks to such anomalies of this phenomenon is life likely to be in the form that is now on the planet.
Humanity has been interested in this miracle since ancient times. Even the philosopher Aristotle in the 4th century BC announced that water is the beginning of everything. In the 17th century, the Dutch mechanic, physicist, mathematician, astronomer and inventor Huygens recommended setting the boiling coefficients of water and ice thawing as the main levels of the thermometer scale. But what is evaporation, mankind learned much later. In 1783, the French naturalist and founder of modern chemistry, Lavoisier reproduced the formula - H2O.
Water properties
One of the incredible qualities of this substance is the ability of H2O to be in three different states under ordinary conditions:
- in solid (ice);
- fluid;
- gaseous (evaporation of liquid).
In addition, water has a very high density when compared with other substances, as well as high heat of vaporization and latent heat of fusion (the amount of heat absorbed or released).
2 has one more quality - the ability to vary its density from a change in the thermometer. And the most amazing thing is that if this quality were not there, the ice could not swim, and the seas, oceans, rivers and lakes would freeze to the bottom. Then life on earth could not exist, because it is ponds that are the first refuge of microorganisms.
H2O cycle in nature
How is this process going? Circulation is a continuous procedure, because in the world everything is interconnected. With the help of the cycle, conditions are created for the existence and development of life. It occurs between bodies of water, land and the atmosphere. For example, in the collision of clouds with cold air, large drops appear, subsequently falling in the form of precipitation. Then the evaporation process takes place, in which the sun heats the plane of the earth, water bodies, and the liquid rises up into the atmosphere.
Vegetation takes moisture from the soil, and water is circulated from the surface of the leaves. This procedure is called transpiration and is a physical and biological process.
The atmospheric layers saturated with steam and located near the earth are then made lighter and begin to move up. The smallest droplets of water in the atmosphere are restored approximately every eight to nine days.
Evaporation occurs due to the cycle, and it is an important component in the circulation of H2O in nature. This process consists of converting water from a liquid or solid state to a gaseous state and the entry of steam inaccessible to the eye into the air.
Evaporation and Evaporation
And what is the difference between the concepts of "evaporation" and "evaporation"? First, consider the first term. This is an indicator of the climate of the area, which determines how much liquid has evaporated from the surface to the maximum. If we take into account that the moisture content of the territory, as noted by G. N. Vysotsky, consists of the ratio of precipitation to evaporation, then this is the most important indicator of the microclimate.
There is a certain dependence: if evaporation is less, then moisture is more. The described process is based on air humidity, wind speed and depends on them.
And what is evaporation? This is a phenomenon in which, in a certain phase, a substance transforms from liquid to vapor or gas. The inverse effect of this process is called condensation. If we compare these two phenomena, it is easy to determine how accessible are water or ice resources for evaporation.
Evaporation Process: Conditions
In the air there is always a certain number of H2O molecules. This indicator varies depending on certain conditions and is called humidity. This is a coefficient that measures the volume of water vapor in the atmosphere. Depending on this, the climate of the localities varies. Humidity is everywhere. There are two types of it:
- Absolute - the number of water molecules in one cubic meter of atmosphere.
- Relative - percentage of vapor to air. For example, if the humidity is 100%, this means the atmosphere is completely saturated with water particles.
The higher the evaporation temperature, the more H2O molecules are contained in the air. So, if the relative humidity on a hot day will be 90%, then this is an indicator that the atmosphere is extremely saturated with tiny droplets.
Particulars
For example, in a room with high humidity, the water in it will not evaporate at all. Although if the air is dry, the steam saturation process will become continuous until it is completely filled with it. With a sudden cooling of air, water vapor that has saturated it before will disappear without stopping and will settle in the form of dew. But in the case of heating the air, which is sufficiently humidified, the saturation process will resume.
The higher t °, the more intense the evaporation, and the so-called vapor pressure, which saturates the space, also increases. Boiling occurs when the vapor pressure is equal to the elasticity of the gas that surrounds the liquid. The boiling point varies depending on the gas pressure around and becomes larger when it rises.
Does evaporation occur quickly
As you know, the process of converting water into steam is directly related to the existence of liquids. Therefore, we can conclude that this phenomenon is very important for nature and industry.
In the process of studying and experimentation, the evaporation rate was revealed. In addition, some of the phenomena accompanying it became known. But they look very controversial and until today their nature is still not clear.
Note that the evaporation rate depends on many factors. They can influence it:
- size and shape of the container;
- weather conditions;
- t ° fluid;
- atmospheric pressure;
- composition and origin of the water structure;
- the nature of the surface from which evaporation occurs;
- some other reasons, for example, electrification of a liquid.
Once again about water
Evaporation is carried out from everywhere where there is liquid: lakes, ponds, wet objects, integuments of bodies of people and animals, leaves and stems of plants.
For example, sunflower during its short life gives air moisture in the amount of 100 liters. And the oceans of our planet release about 450,000 cubic meters of fluid per year.
The evaporation temperature of water can be any. But, when it gets warmer, the process of fluid transfer is accelerated. Note that during the summer heat, puddles on the surface of the earth dry much faster than in spring or autumn. And if it is windy on the street, then, accordingly, the evaporation proceeds even more intensively than in those situations when the air is calm. This property also has snow and ice. If you hang clothes to dry outside in the winter, then it will first freeze and then dry in a few days.
The temperature of evaporation of water at 100 ° C is the most intense factor at which the named process achieves the highest result. At this time, boiling occurs when the liquid intensively turns into steam - a transparent, invisible gas.
If viewed under a microscope, then it consists of single H2O molecules located far from each other. But when the air cools, water vapor becomes visible, for example, as fog or dew. In the atmosphere, this process can be observed thanks to the clouds that appear due to the transformation of water droplets into visible ice crystals.
Nature statistics
So, what is evaporation, we found out. Now we note the fact that it is closely related to air temperature. Therefore, during the day, the largest number of cubic meters of water turns into steam at about noon. In addition, this process is most intense in the warmer months. The strongest evaporation in the annual cycle is observed in the middle of summer, while the weakest falls in the winter.
Everyone is responsible for the environment. To understand this proposition, it is necessary to catch a simple calculation. Imagine that a person speaks of his helplessness with respect to the prevention of an environmental disaster and believes that he is unable to do anything. But if you multiply any one insignificant action of the individual by 6.5 billion people on earth, it will become clear why it is worth reasoning like that.