What causes convection currents in a gas or liquid?

Convection currents are caused by a temperature difference in gases and liquids. As one area becomes warmer than another the molecules have more energy and start vibrating more vigorously thus spreading out and becoming less dense. This means that the less dense parts will become more buoyant causing them to rise.

Explanation:

Convection currents are caused by a temperature difference in gases and liquids.  

Explanation:

As one area becomes warmer than another the molecules have more energy and start vibrating more vigorously thus spreading out and becoming less dense. This means that the less dense parts will become more buoyant causing them to rise.

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