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
Ariel Atom ones. In 2005 "Track and Race Car" magazine published the results of a comprehensive test of a range of cars, from the Porsche 911 Carrera S, Ford GT, BMW M5 to the Caterham CSR 260. The supercharged Ariel Atom 2 won the 0–161–0 km/h (0–100–0 mph) test by a clear margin at 10.88 seconds, ahead of the Caterham CSR 260 (11.41) and the Ford GT in fourth (13.17). The following year, the Atom won "Autocar"s 0–100 mph challenge as the new Ariel Atom 2 300 bhp supercharged edition achieved a time of 6.86 seconds, and then stopped from 100 in