Read First –
- What is Matter? What is its Characteristics?
- States of Matter
- Can Matter change its State?
- Evaporation (Liquid changes into Gas)
[dropcap]Why[/dropcap] do we see water droplets on the outer surface of a glass containing icecold water?
do we find dew drops, especially in the early morning on the leaves?
The water vapor present in air, on coming in contact with the cold surface (say outer surface of glass of ice-cold water, leaflet in night), loses energy and gets converted to liquid state, which we see as water droplets. Condensation is the opposite of evaporation.
It takes place when water vapor in the air condenses from a gas state, back into a liquid form, and leaves the atmosphere, returning to the surface of the Earth. It is the process which creates clouds, and so is necessary for rain and snow formation as well. A very important part of this process is the release of the latent heat of condensation. This is the heat that was absorbed when the water was originally evaporated from the surface of the Earth, a process which keeps the Earth’s surface climate much cooler that it would otherwise be if there were no water. The heat removed from the surface through evaporation is thereby released again higher up in the atmosphere when clouds form.