What is caused by the action of hot material rising and cool material sinking?

Heat transfer

Explanation:

Hot material such as hot air or liquid is more dense that cool material so it will rise. As it does so the cool material will sink towards the source of heat that is making the hotter materials hot and get heated as well which will enable it to rise and the whole cycle repeats.

This type of heat transfer is called Convection and it is very important to processes occurring on earth from basic things such as how water is heated in a kettle to how rainclouds are formed in the atmosphere.

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 correct answer is b