The answer is false. I know for a fact it is but i dont remember which ones.
Adding neutron to the nucleus creates new isotopes of that element. Mass of the nucleus will increase if you add neutron to it but element will remain the same. If you add proton to the nucleus, mass of the nucleus will change but also element will also change. That is, atom of the element will change.
That would be crazy but the world already has certain pieces of matter on it
