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Infra-Red Radiation

• All objects give out and take in thermal radiation, which is also called infrared radiation. The hotter an object is, the more infrared radiation it emits.
• Very hot objects may glow, such as the heating element in a toaster or electric fire. Other hot objects may not glow, such as an iron.
• Some surfaces are better than others at absorbing and reflecting infrared radiation:
• black surfaces are good absorbers
• shiny surfaces are good reflectors
• When an object absorbs infrared radiation, its temperature increases. Food, for instance, begins to cook when its surface absorbs infrared radiation.

Conduction

Convection