why water in sea and river evaporates when it not reaches boiling temperature?

Question

i learned that water evaporates when it reaches boiling temp. Then how water in sea and lakes evaporates when it is not boiling

Answer 1

You are confused between Evaporation and Boiling.

Evaporation is one of the two forms of vaporization. It is the process whereby atoms or molecules in a liquid state (or solid state if the substance sublimates) gain sufficient energy to enter the gaseous state. It is the opposite process of condensation.

The thermal motion of a molecule of liquid must be sufficient to overcome the surface tension and evaporate, that is, its kinetic energy must exceed the work function of cohesion at the surface. Evaporation therefore, proceeds more quickly at higher temperature, at higher flow rates between the gaseous and liquid phase and in liquids with lower surface tension (i.e. higher vapor pressure).

EVAPORATION OCCURS AT ALL Temperatures.

This must answer your question.

Answer 2

Water evaporates at temperatures well below the boiling point, though the warmer it is, the faster it'll evaporate. Did you know that even water ice evaporates? That process is called sublimation. It's why there's no water on the moon - some scientists thought maybe there'd be ice just beneath the surface that could be brought up and used by astronauts in a permanent moon base. But there's no ice there because it, too, would have sublimated into water vapor and disappeared over the millions of years that have passed since water first might have appeared on the moon. And it's really doubtful there ever was any water on the moon in the first place. Too bad for NASA's planned permanent base - they'll have to carry their own water with them and try to recycle as much of what they use as possible. That would be verrrrrry expensive!

Answer 3

The this is that there is some thing called equilibrium. That is when 2 opposite processes happen without a noticeable change. Water in rivers and seas evaporates because there is room for the water to evaporate and become part of the air. When the air gets saturated with water, then the water vapour condences and it rains. water doesn't only evaporate at bioling point, it evaporates until the surrounding air is saturated (at cool temp. this may be slow)

Answer 4

First understand that water is converted into vapour at any temperature. When you open a refrigerator, you can observe water vapour is coming out. The temperature inside the refrigerator is very less than the room temperature. Observe the water vapour coming out of water in a kettle on a stove, even before water begins to boil. Thus the process of vaporization of water takes place at any temperature. Consider water at room temperature. Even at this temperature water gets evaporated. When we slowly rise the temperature the rate of evaporation increases. Thus higher the temperature greater is the rate of evaporation. Now let us assume that the atmospheric pressure is one atmosphere. (Near sea level places) When the temperature reaches 100 degree centigrade water begins to boil. At this temperature, whatever be the amount of heat we add, (i.e. even if we increase the flame of the burner) the temperature will not rise and all the water gets evaporated into steam at this constant temperature. This we call as the boiling temperature. Thus given the pressure there is a maximum temperature above which we cannot increase the temperature of water. This temperature is boiling temperature at that pressure. And below this temperature, water is being continuously evaporated. When the pressure is lowered the boiling temperature is lowered. That is even at low temperature water begins to boil. Vaporization consists in the separation of fast moving particles from the surface of a liquid. When heat is applied, the temperature increases and it is the indication of the increase in the speed of the fast moving particles. The particles are removed quickly from the surface of the liquid. If the vaporized molecules are continuously removed from the surface of the liquid, the process continues until all of the liquid has been transformed into vapour. In a closed vessel, two processes take place. Water vapour condenses to water and water gets converted into vapour. The vaporization of process continues until a dynamic equilibrium corresponding to the given temperature has been established. If equilibrium exits, we say that the vapour is saturated. Other wise the liquid will completely vaporize without equilibrium being established. Finally regarding water, if the pressure is 10 atmosphere, then water will boil at 150 degree centigrade. Under this pressure you cannot raise the temperature of water because the temperature will not rise till all water is converted into vapour. But under the same pressure water will evaporate even the temperature is below 150 degree centigrade.

Answer 5

It can be accurately modelled by a thermodynamic quantity called the Gibbs Free Energy. If there are no water molecules in the air, the total energy is high, and if there are a few, it is lower, so the system moves to the state of minimum energy.

As the temperature increases, the distribution with the minimum energy changes, and the system moves to that state. The freezing and boiling points are where the energy calculations change quite abruptly, but it changes slowly all the way in between.

Answer 6

NO actually water evaporates under the boiling point.But water in the sea does not evaporate fast as the amount of salt is lesser than water.

Answer 7

Oceans | Sea | Salt | Marine Life | Pacific Ocean | Atlantic Ocean | Water | Evaporate | Sunlight | Earth
... it picks up small amounts of mineral salts from the rocks and soil of river beds. ... Ocean water evaporates through the process of the water cycle, but the salt ...
http://www.kidzworld.com/site/p5316.htm

Answer 8

When water is boiled it vapourizes at 100 degree.This happens fast and u can see it but evaporation is very slow and cannot be noticed

Answer 9

it doesn't literally boil but it evaporates only at boiling temperature.

Answer 10

water will always evaporate................it just happens very fast when boiling