Definition of proton in English:

proton

noun

Physics
  • A stable subatomic particle occurring in all atomic nuclei, with a positive electric charge equal in magnitude to that of an electron, but of opposite sign.

    • ‘Overall, atoms are neutral and the number of protons in their nuclei equals the number of electrons.’
    • ‘An alpha particle consists of two protons and two neutrons; it is the nucleus of a helium atom.’
    • ‘Its atoms have a nucleus of two protons and two neutrons, orbited by two electrons.’
    • ‘The matter was composed primarily of an ionized gas of electrons, protons, and helium nuclei.’
    • ‘The strong force also attracts protons to protons or neutrons to neutrons.’

Origin

1920s: from Greek, neuter of prōtos first.

Pronunciation:

proton

/ˈprōˌtän/