Evaporation: Definition, Process & Factors Impacting Evaporation

Definition of Evaporation

Evaporation is the process by which particles undergo a spontaneous shift from the liquid stage to the gas stage. Evaporation is the reverse of condensation. For evaporation to take place, molecules in a liquid should be near the surface area, need to be moving far from the body of the liquid, and must have sufficient kinetic energy to leave the interface.

When molecules do escape, the general kinetic energy of the remaining particles is decreased. This decreases the temperature of the liquid and is the basis for the phenomenon of evaporative cooling.

Process of Evaporation

Evaporation takes place when the liquid converts into a gas. The process begins when the molecules of the liquid get energy in the form of heat. They then develop into a vapor after this acquiring of energy.

Another important thing to comprehend is that this process occurs only on the surface of the liquid and not throughout the whole body or volume. Throughout evaporation, the pressure of the surrounding environment is higher than that of the vapor.

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Evaporation Causes Cooling

Evaporation causes cooling naturally. The underlying principle behind this is, in order to change its state, the matter must either get or lose energy. When it comes to the change of stage from liquid to gas, particles of matter require energy to overcome their potential energy by their kinetic energy.

So, the liquid takes this energy from its environment. Usually, when energy transfer occurs, it leads to a boost or decrease in the temperature level of the substance, depending on whether the energy is being transferred from the compound to the environment or vice versa. Nevertheless, there are exceptions to this rule. Although there is an increase in the temperature level of the compound until the boiling point is obtained during evaporation, stage modification leads to no observable heat transfer.

The particles of the substance soak up heat continuously from the surroundings and hence cool the surroundings until they reach the boiling point, after which they start to break free from the liquid and develop into vapor. Given that there is no change in temperature till the evaporation procedure is complete i.e., the whole liquid gets converted into vapor, the amount of energy needed for this phase change is called the latent heat of vaporization, where the word ‘latent’ indicates hidden, suggesting this heat will not change the temperature reading on a thermometer.

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Factors Impacting Evaporation

Evaporation occurs at all temperatures from the surface of a liquid. The rate of evaporation is affected by different factors.

Surface Area

If the area is increased, then the amount is of liquid that is exposed to air is bigger. More molecules can get away with a larger area.


The water molecules move quickly when the water is warmed. This makes the particles escape much faster. Higher temperature levels lead to an increase in vaporization as more particles get kinetic energy to convert into vapor. For instance, boiling water evaporates faster than fresh tap water.


Humidity means the amount of vapor present in the air. The air around can just hold a specific amount of vapor at a certain time and a specific temperature level. If the temperature level boosts and the wind speed and humidity remain continuous, then the rate of evaporation will increase since warmer air can hold more water vapor than cooler air.

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Particles of vapor move away when the speed of wind increases. This leads to a decline in the amount of water vapor in the atmosphere.

Evaporation in Daily Life

Our everyday lives experience evaporation on a regular basis. For instance, when one carries out laborious activities or feels hot, their body produces sweat. Likewise, the sweat happening on our skins gets its energy from the body which eventually vaporizes and produces a cooling effect.

Additionally, when we get out after a bath, our body dries up due to this procedure just. To try it out, leave a glass filled with water out in the heath, you will notice gradually the water level will start reducing. This is an extremely common example of water evaporating into the air.