Answer:
Chain reaction is possible by neutron
Step-by-step explanation:
Nuclear reaction is mainly two types,
⇒ Nuclear Fission : heavy atom split into two light atom.
Ex. Uranium, thorium
⇒ Nuclear fusion : lighter atom combine together
Ex. Hydrogen to helium
In fusion reaction the large amount of energy is produced as compare to fission reaction.
Sun gets brighter by fusion reaction.
In case of uranium fission reaction is possible by colliding neutron.