Mass is conserved in nuclear fusion. p+Li6 fusion is a single proton (a bare hydrogen nucleus) smacking into an atom made of 3 protons and 3 neutrons. (Lithium

Mass is conserved in nuclear fusion. p+Li6 fusion is a single proton (a bare hydrogen nucleus) smacking into an atom made of 3 protons and 3 neutrons. (Lithium-6) The reaction products have to have the same number of protons and neutrons as what goes in.