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### Theory:

Convection:
When we heat the water in the vessel, water molecules at the bottom receive heat energy and move upward. Then the molecules at the top come down and get heated. This mode of heat transfer is known as convection. Air in the atmosphere also follows the same principle while heating. Thus, the form of heat transfer from higher temperature regions to lower temperature regions by the actual movement of molecules is known as convection. Convection takes place in liquids and gases.

Convection is the movement of fluid (liquid and gasmolecules from higher temperature regions to lower temperature regions.
Convection

Convection Process
Example:
The following are some examples of convection in daily life.
• Boiling of water - the molecules with the higher density move at the bottom (Coldwater). In contrast, the less dense molecules (Hot water) move upwards, resulting in the circular motion of the molecules so that water gets heated.
• The formation of the land and sea breeze is due to the convection of air.
• Wind flows from one region to another by convection.
• In warm-blooded animals, blood circulation takes place with the help of convection, and it helps maintain the body temperature.
• In hot air balloons, heat is transferred by convection, and so the balloon raises.
• In refrigerators, cool air moves downwards and replaces the hot air because of convection.

Note: Heat transfer by radiation is visible to our eyes. When a substance is heated to $$500$$$$°C$$, the radiation becomes visible as a dull red glow, and the skin senses the warmth. Further heating rapidly increases radiation, and its perceived colour becomes orange, yellow and finally white.