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.
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