The mass of protons is not enough to account for the total mass of atom. In 1932, James Chadwick resolved this issue. He discovered neutron, an uncharged massive particle that also resides in the nucleus. 17
The mass of protons is not enough to account for the total mass of atom.In 1932, James Chadwick resolved this issue. He discovered neutron, an uncharged massive particle that also resides in the nucleus.17