What drives the convection ?

Convection occurs through the movement of particles. As particles become heated, the molecules move faster and faster, and as molecules move apart, density decreases. The warmer, less dense material rises compared to the surrounding cooler, higher density material.

Explanation:

the relative standard reduction potential of the half-cell in which reduction occurs; more positive than the other half-cell. reduction is a chemical process in which electrons are added to an atom or an ion; it always occurs accompanied by oxidation of the reducing agent.

the glands which are associated with each description is given below: