Is fission or fusion used in nuclear power plants? which is more powerful? which is a cleaner source of energy? why do you think one used as an energy source in power plants while the other is not?

Nuclear fission

Explanation:

Nuclear fission is used in energy plants. In physics and physical sciences, nuclear fission reaction occur when there is a split in the nucleus of an atom. The process releases one or more neutrons in the case of the fissioning of a nucleus with a high mass number. A neutron with a suitable energy interacts with a nucleus to induce fission.

The fusion results in a generation of high heat and is difficult to control. Hence the limited use if not at all,

it's c. elements are placed in rows based on how may valencies electrons have.