Convection: rising heat

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Q1: Why do you put a convection heater near the floor in a room?

[Answer]

Here are two important properties of liquids and gases: liquids and gases both move easily; hot materials get lighter as they warm up.

If a liquid, like water, or a gas like air, is heated from below, it soaks up heat and gets lighter. Because it can move easily, the liquid or gas then rises, forcing the colder liquid or air down to take its place.

This overturning way of sharing heat is called convection.