Describe radiation and give two real-life applications.

Radiation is the transfer of heat by electromagnetic waves; it does not require any medium and can occur through vacuum.

Example 1: The Sun heats the Earth by radiation; sunlight carries energy across space to warm land and water.

Example 2: You feel warmth near a fire because the fire radiates heat as infrared and other electromagnetic waves.

Practical note: Light-coloured clothes reflect more radiation and keep us cooler in hot weather, while dark-coloured clothes absorb more radiation and keep us warmer in cold weather.