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.
Atom (system on chip) 2011, Intel announced an accelerated roadmap for Atom SoC. The 22 nm Silvermont microarchitecture was scheduled for 2013 release, and release of the 14 nm Airmont microarchitecture was scheduled for 2014. It has been reported that Silvermont-based Atom SoCs will be codenamed Tangier (Merrifield smartphones), Valleyview (Bay Trail tablets), will be available in single-, dual- and quad-core versions, and Valleyview will include Intel's 7th generation GPU, allowing for 4–7× improvement over existing Atom GPUs. Other upcoming Silvermont-based Atom SoCs include Rangeley and Avoton (part of Edisonville platform). Airmont-based Atom platforms will be codenamed Moorefield (smartphones) and Cherry Trail (tablets) using