The article describes what steam is, what types of it are and how water vapor is used in industry and everyday life.
Physics
One of the main sciences that help to find out the structure of the surrounding world and some of its processes is physics. There are many interesting reactions going on around us every second. We have long been accustomed to many of them and do not pay attention to them. Moreover, in everyday life, few people think about the nature of the burning of the Sun, or the occurrence of water vapor, which has a huge impact on the climate. And although the processes described above have been studied quite well, we will still consider the question of what steam is. By the way, it can be formed as a result of not only boiling or evaporation of water, but also other reactions of various substances, but first things first.
Definition
Vapor is the gaseous state of matter, provided that this phase is in equilibrium with other aggregate states of this matter. The process itself, as a result of which steam appears, is usually called vaporization, and the reverse process is called condensation. So now we know what steam is. By the way, usually when the word “steam” is mentioned, people almost always mean the steam that is obtained fromordinary water, although, as mentioned above, many substances can take on this state of aggregation.
In addition, it is customary to distinguish two main types: saturated and unsaturated. But these definitions apply only to substances that are chemically pure. Let's analyze them in more detail.
What is unsaturated steam?
So they call it when it could not reach an equilibrium, called dynamic, in relation to the fluid from which it was formed. Often such a definition is confused with thermodynamic, which is wrong. If you compare the pressure of unsaturated steam with saturated, then it will always have a lower value.
When unsaturated vapor appears on the surface of a liquid, the process of its formation proceeds faster and prevails over the reverse process (as we have already said, it is called condensation). And as a result, the liquid gradually becomes less and less.
Now consider what saturated steam is.
Saturated steam
Saturated steam is called when it was able to achieve dynamic equilibrium with the liquid from which it was obtained. Simply put, in this case, evaporation equals condensation, and unlike the situation with unsaturated steam, the amount of liquid can remain unchanged. Now we know what steam is and its types.
If, for example, you compress a vapor that is in equilibrium with its liquid, then this balance will gradually disappear, andthe condensation will become more and more intense until, due to a change in the density of the gaseous substance, dynamic equilibrium is restored again.
Depending on the type of liquid, dynamic equilibrium with vapor appears at different values of its density. This is due to the fact that all substances have a different force of intermolecular attraction.
Water vapor
And yet most often people understand this word as the gaseous state of water that is familiar to everyone. If you look in the encyclopedia, you can find the main defining characteristics of steam: the absence of color, smell and getting it, in fact, from water.
We've all noticed it repeatedly, whether it's boiling water for cooking or evaporating moisture from hot pavement after rain. But if you think about it and remember the periods of the industrial and technological revolution, it becomes clear that steam is of great importance in human life. The physics of this phenomenon is such that the gaseous state of water occupies a volume ten times greater than its original liquid form. It was this observation that at one time gave impetus to the development of technology.
It all started with the first steam engines, and a little later, "self-propelled" carts, as vehicles with such engines were called. But such cars were brought to working condition for a very long time, had low speed and poor handling. Everything changed only with the invention of steam locomotives.
Besides this, water is also a good coolant and is used in many systemscooling, and if their circuit is not closed, then steam also appears as a result. In our time, it is sometimes specially brought to a gaseous state, but not in primitive engines, but at nuclear power plants, where turbines of electric generators are rotated by steam.
Evaporated water is also of great importance in the climate. Having risen to a height where the temperature is much lower, the steam condenses and falls to the surface of the earth in the form of rain. Snow appears in much the same way.
Well, in the end, they cook dietary and simply he althy food for a couple.
Under the right conditions, the steam forms a mist near the surface of the earth.
Now we know what steam is and how it happens.
