Question

What is condensation? How does it occur?

Short answer

Answer: Condensation is the process by which water vapor in the air changes its state from a gas to a liquid when it cools down and loses energy. The steps involved in its occurrence are: (1) cooling of air, (2) water vapor meeting the dew point, (3) formation of tiny water droplets, and (4) visible signs of condensation, such as dew on the grass, fog in the air, or water droplets on a cold drink glass.

Step-by-step solution

Definition of Condensation

Condensation is the process by which water vapor in the air changes its state from a gas to a liquid. This transformation occurs when the water vapor cools down and loses energy.

Cooling of Air

Condensation occurs when the air temperature decreases. This can happen in several ways, such as: (1) the air comes into contact with a cold surface, (2) the air rises and expands due to a decrease in atmospheric pressure, or (3) the air mixes with cooler air from a different location.

Water Vapor Meets Dew Point

When the air is cooled, its capacity to hold water vapor decreases. The temperature at which air can no longer hold all of the water vapor it contains is called the dew point. When the air temperature drops to the dew point, excess water vapor will condense into liquid water.

Formation of Tiny Water Droplets

When the water vapor molecules come in contact with a surface, they attach to it and form tiny water droplets. This surface can be a solid, like the ground or a window, or it can be tiny particles in the air, such as dust or pollen. Collectively, these water droplets are known as condensation.

Visible Signs of Condensation

Condensation can become visible in various ways, such as dew on the grass in the morning, fog in the air, or water droplets on a cold drink glass. In each case, the air has cooled to its dew point, and excess water vapor has condensed into liquid water droplets.