Define what plates are.

Each of the several rigid pieces of the earth's lithosphere which together make up the earth's surface.

Explain how the different temperatures of the mantle causes the earth’s plates to move (Convection Current).
Plates at our planet's surface move because of the intense heat in the Earth's core that causes molten rock in the mantle layer to move. It moves in a pattern called a convection cell that forms when warm material rises, cools, and eventually sink down. As the cooled material sinks down, it is warmed and rises again