Definition of 'proton'

Word Frequency

proton

(proʊtɒn )

Word forms: plural protons

countable noun

A proton is an atomic particle that has a positive electrical charge.

[technical]

Word Frequency

proton in British

(ˈprəʊtɒn )

noun

a stable, positively charged elementary particle, found in atomic nuclei in numbers equal to the atomic number of the element. It is a baryon with a charge of 1.602176462 × 10–19 coulomb, a rest mass of 1.672 62159 × 10–27 kilogram, and spin 1⁄2

Word origin of 'proton'

C20: from Greek prōtos first

Word Frequency

proton in American

(ˈproʊˌtɑn ; prōˈtänˌ)

noun

Particle Physics

a nucleon carrying a positive charge equal to the negative charge of an electron and having a mass of c. 1.673 × 10-27kg (c. 938.2796 MeV/c2, c. 1,836 times the mass of an electron): the number of protons in an atom determines the atomic number of a chemical element

Word origin of 'proton'

ModL < Gr prōton, neut. of prōtos, first: see proto-

Example sentences containing 'proton'

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The new fund will look to back innovations that advance the treatment of brain tumours, including medicines and proton beam machines. Times, Sunday Times (2016)The new fund will look to back innovations that advance the treatment of brain tumours, including medicines and proton beam machines. Times, Sunday Times (2016)It specialises in funding proton beam treatment. The Sun (2014)He said he had offered to sell his property to pay for the proton beam. Times, Sunday Times (2014)A proton beam stops and is much less harmful, although the dose of radiation is the same. The Sun (2015)Most Western countries have numerous proton beam establishments, which in some cases have been in use for years. Times, Sunday Times (2013)