Atom center of mass, although strictly speaking these particles are believed to be point-like and cannot be said to be rotating. Spin is measured in units of the reduced Planck constant (ħ), with electrons, protons and neutrons all having spin ½ ħ, or "spin-½". In an atom, electrons in motion around the nucleus possess orbital angular momentum in addition to their spin, while the nucleus itself possesses angular momentum due to its nuclear spin. The magnetic field produced by an atom—its magnetic moment—is determined by these various forms of angular momentum, just as a rotating charged object classically produces a magnetic
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