Definition of proton in English:

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Pronunciation: /ˈprəʊtɒn/


A stable subatomic particle occurring in all atomic nuclei, with a positive electric charge equal in magnitude to that of an electron.
Example sentences
  • Overall, atoms are neutral and the number of protons in their nuclei equals the number of electrons.
  • The matter was composed primarily of an ionized gas of electrons, protons, and helium nuclei.
  • An alpha particle consists of two protons and two neutrons; it is the nucleus of a helium atom.

The mass of the proton is 1,836 times greater than that of the electron. The atoms of each chemical element have a characteristic number of protons in the nucleus; this is known as the atomic number. The common isotope of hydrogen has a nucleus consisting of a single proton.



Pronunciation: /prə(ʊ)ˈtɒnɪk/
Example sentences
  • The organic purity of the organoarsenic species was determined by protonic nuclear magnetic resonance.
  • The rate of the former, productive reaction is determined by the protonic conductance of the consumer.
  • It consists of an interdependence between the electronic and protonic captures, which results from electrostatic interactions between redox and protonatable groups.


1920s: from Greek, neuter of prōtos 'first'.

Words that rhyme with proton


For editors and proofreaders

Line breaks: pro¦ton

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