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.
Captain Atom Captain Atom himself when he first became Monarch. Mon-El appears and helps Captain Atom escape, taking him to the Justice League's satellite, where the League members declare that they are going to bring him to justice for his actions as Monarch. After a struggle with the League, Captain Atom tells them what he can remember. The League reminds him he was a hero who once saved the planet. He feels he has changed from the man he once was, and that he needs to go back to the magic world to make right what he has done. The Shadowpact are