You must have see small water droplets on the blades of grass and leaves of plats shining like pearls I the early hours of morning. These water drops are called dew. Many people still think that dewdrops are like rainwater, which fall on the earth form the sky at night, which is not true.
Dewdrops are formed when hot water vapors condense on cold surface
The air around us contains water vapor, which we call moisture or humidity. Hot air contains more moisture as compared to cold air. At night, when the hot air comes in contact with some cold surface, water vapor present in the air condenses on the cold surface in the form of droplets. These tiny drops of water are called dewdrops.
The process of dew formation can be see in a simple experiment. Take a tumbler and place it on a table. Now put some ice or ice cold water inside ether tumbler. You will notice that after some time, small drops of water appear on the outré surface of the tumbler. These water drops are formed by the condensation of the water vapors present in the air when it comes in contact with the cold surface of the tumbler. Similarly, the water vapor in the air condenses on the cold surfaces of grass, flowers and leaves to form dew drops.
The dew formation is more conspicuous when the sky is clear, and less when it is cloudy. When the sky is clear, it becomes coiler at nights, therefore, there is more condensation of water and hence more dew formation. But when it is cloudy, trees and plants are not able to radiate and lose heat and therefore do not get cooled in the night. Hence, there is less dew formation. As the sun rises, it begins to get warmer and these dewdrops evaporate into air and disappear.
