6. Explain convection.

• The heat is transferred by rays. All hot objects give out conduction. It can happen in a vacuum where there are no particles.
• The heat is transferred by a moving current, by fluids. The hot fluids, when heated, rise because they are lighter, and the cold fluid replaces them.
• When heat energy is absorbed, particles vibrate. Seeing the particles of a solid are close together, the heat gets passed on.