proton

noun
pro·​ton | \ ˈprō-ˌtän How to pronounce proton (audio) \

Definition of proton

: an elementary particle that is identical with the nucleus of the hydrogen atom, that along with the neutron is a constituent of all other atomic nuclei, that carries a positive charge numerically equal to the charge of an electron, and that has a mass of 1.673 × 10−27 kilogram

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Other Words from proton

protonic \ prō-​ˈtä-​nik How to pronounce protonic (audio) \ adjective

Examples of proton in a Sentence

Recent Examples on the Web

Pentaquarks should occasionally form when protons are bombarded with gamma ray photons, as physicists at Thomas Jefferson National Accelerator Facility in Newport News, Virginia, are trying to do. Adrian Cho, Science | AAAS, "Exotic particles called pentaquarks may be less weird than previously thought," 5 June 2019 WIMPs, despite their puny name, are thought to have a mass as much as a thousand times more than standard matter’s protons. Joe Lindsey, Popular Mechanics, "Filling the Void: What Is Dark Matter?," 28 May 2019 Solar proton events occur when a shift in the Sun’s magnetic field releases sudden blasts of energetic solar particles that engulf Earth’s magnetosphere. Jill Kiedaisch, Popular Mechanics, "Evidence of a Monstrous, Ancient Solar Storm Found Hidden in Greenland's Ice," 14 Mar. 2019 But hydrogen ions, single protons, have positive electric charges and naturally repel each other. Tim Folger, Discover Magazine, "How Quantum Mechanics Lets Us See, Smell and Touch," 24 Oct. 2018 These particles, primarily composed of electrons, protons, and helium nuclei (known as alpha particles), fly all over the solar system. Jay Bennett, Popular Mechanics, "The New Science of the Sun Will Be Astounding—And Possibly Terrifying," 9 Aug. 2018 Perhaps there could even be a kernel inside the shell of neutrons and protons with that elusive negative mass required to power something like the Alcubierre warp drive. Jennifer Ouellette, Ars Technica, "The Orville blends science fiction and science fact into a winning mix," 29 Dec. 2018 Scientists discovered in 1912 that subatomic particles — the building blocks of matter, such as protons, electrons, muons, neutrinos, and quarks — hit the Earth every day. Brian Resnick, Vox, "10 science stories in 2018 that made us go, “Whoa, that’s awesome”," 18 Dec. 2018 Each atom of the stuff packs a whopping 118 protons into its dense center. Michael Block, Scientific American, "The Quest for Superheavy Elements and the Island of Stability," 19 Mar. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'proton.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of proton

1920, in the meaning defined above

History and Etymology for proton

Greek prōton, neuter of prōtos first — more at proto-

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Statistics for proton

Last Updated

10 Jun 2019

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Time Traveler for proton

The first known use of proton was in 1920

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More Definitions for proton

proton

noun

English Language Learners Definition of proton

physics : a very small particle of matter that is part of the nucleus of an atom and that has a positive electrical charge

proton

noun
pro·​ton | \ ˈprō-ˌtän How to pronounce proton (audio) \

Kids Definition of proton

: a very small particle that exists in the nucleus of every atom and has a positive charge of electricity

proton

noun
pro·​ton | \ ˈprō-ˌtän How to pronounce proton (audio) \

Medical Definition of proton

: an elementary particle that is identical with the nucleus of the hydrogen atom, that along with neutrons is a constituent of all other atomic nuclei, that carries a positive charge numerically equal to the charge of an electron, and that has a mass of 1.673×10−24 gram

Other Words from proton

protonic \ prō-​ˈtän-​ik How to pronounce protonic (audio) \ adjective

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More from Merriam-Webster on proton

Rhyming Dictionary: Words that rhyme with proton

Spanish Central: Translation of proton

Nglish: Translation of proton for Spanish Speakers

Britannica.com: Encyclopedia article about proton

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