Atom bombardment ejects what appeared to be hydrogen nuclei. By 1920 he had accepted that the hydrogen nucleus is a distinct particle within the atom and named it proton. Neutrons have no electrical charge and have a free mass of 1,839 times the mass of the electron, or , the heaviest of the three constituent particles, but it can be reduced by the nuclear binding energy. Neutrons and protons (collectively known as nucleons) have comparable dimensions—on the order of —although the 'surface' of these particles is not sharply defined. The neutron was discovered in 1932 by the English physicist James Chadwick.
Empire of the Atom is kept alive because one of the atom priests wants to conduct an experiment to see what will happen if the boy, unlike other mutant children, is given the full education of an atom priest. In his teens the mutant boy Clane helps his father win a war with Mars. He also continues his studies while his grandfather, who is Lord Leader, and his tutors protect him from the Machiavellian intrigues swirling around him, especially those of his grandmother Lydia. Reaching his majority, Clane turns his estate into a laboratory where he can test new inventions and machines that he