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 Empire of the Atom Empire of the Atom is a science fiction novel by Canadian American writer A. E. van Vogt. It was first published in 1957 by Shasta Publishers in an edition of 2,000 copies. The novel is a fix-up of the first five of van Vogt's Gods stories which originally appeared in the magazine "Astounding". The remaining Gods stories are collected in "The Wizard of Linn". Author and critic James Blish observed that the plot of the Gods stories resembled that of Robert Graves' "Claudius" novels. Author and critic Damon Knight said that the plot was "lifted almost