When cold water is kept in a glass, small droplets are formed on the surface of the glass after a while. How does this happen? What is this phenomenon called? Can the reverse of this phenomenon happen? If so, what is that process called? Explain with an example. [5 MARKS]
Explanation: 1 Mark each.
1. This phenomenon of water droplets being formed on a cool water bottle is called condensation.
2. Condensation happens because of the temperature difference. The water vapour present in the air cools down due to the low temperature of water inside the glass and forms small droplets of water on the surface of the glass.
3. The reverse of this phenomenon is liquid being turned into gas, and this process can happen.
4. This process is called evaporation. Evaporation is the conversion of a liquid into a gas by application of heat.
5. Example: Heating water turns it into steam.