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.
Children of the Atom (supplement) Children of the Atom (supplement) Children of the Atom is a role-playing game supplement published by TSR in 1986 for the "Marvel Super Heroes" role-playing game. "Children of the Atom" is a supplement for the Advanced Set describing all of Marvel's mutant heroes and villains. "Children of the Atom" is an encyclopedia of mutant-kind, detailing their friends, enemies, homes and equipment. It includes a miniscenario, "Dreamchild." MA1 "Children of the Atom" was written by Kim Eastland and was published by TSR, Inc., in 1986 as a 96-page book with an outer folder. Pete Tamlyn reviewed "Children of the Atom" for