World Wars and the AtomScience & Math Neutron discovered 1932Major James Chadwick identifies the neutron, an uncharged particle in the nucleus, which becomes the tool that splits atoms. ▲ MattersSaveShareTrace roots Longest chain: The Big Bang → First stars ignite → Supernovae seed heavy elements → The Sun forms → Earth forms → First oceans → First life → Photosynthesis evolves → Great Oxidation Event → Complex cells (eukaryotes) → Multicellular life → First animals → Cambrian Explosion → First vertebrates → Jawed fish → Fish walk onto land → The amniotic egg → The Great Dying → Dinosaurs appear → Asteroid ends the dinosaurs → Early primates → Apes split from monkeys → Human line splits from chimpanzees → Walking upright → First stone tools → Genus Homo appears → Homo erectus → Control of fire → First fired clay figures → First pottery → Copper smelting → Bronze Age begins → Shang dynasty → Zhou dynasty and the Mandate of Heaven → Spring and Autumn period → Legalism (Shang Yang) → Qin unifies China → Han dynasty → Magnetic compass for navigation → Gilbert's On the Magnet → Leyden jar → Franklin's kite experiment → Electric battery → Electromagnetism → Electromagnetic induction → Maxwell's equations → X-rays → Radioactivity → Atomic nucleus → Neutron discovered Community notesLoading notes… Learn more ranked by votesDocumentnobelprize.orgThe Nobel Prize in Physics 1935 (Nobel Prize) ↗Editor's pickBookRichard RhodesThe Making of the Atomic Bomb ↗Editor's pickVideoSearch on YouTubeJames Chadwick discovery of the neutron ↗Editor's pick