If a cold piece of metal is added to hot water, the water will

Over time the metal will cool and the water will heat up. Eventually the two objects will have the same temperature

Explanation:

radioactive decay occurs in unstable atomic nuclei – that is, ones that don't have enough binding energy to hold

the nucleus together due to an excess of either protons or neutrons.

d.) circle motion requires a force to give it a centripetal acceleration.