pos·​i·​tron | \ ˈpä-zə-ˌträn How to pronounce positron (audio) \

Definition of positron

: a positively charged particle having the same mass and magnitude of charge as the electron and constituting the antiparticle of the electron

called also antielectron

Examples of positron in a Sentence

Recent Examples on the Web The dance between positron and antiproton in antihydrogen should exactly follow that of the electron and proton in hydrogen. Sophia Chen, Wired, 19 Feb. 2020 In contrast, the higher energies used in the ALPHA experiment slow antiprotons and positrons down enough for the particles to form atoms of antihydrogen for more in-depth study. Jonathan O'callaghan, Scientific American, 19 Feb. 2020 Sometimes, the photon immediately decays into an electron and a positron, which are propelled forward by the photon’s momentum and strike the detector near one another. Quanta Magazine, 7 June 2016 Richard Feynman, a young professor at Cornell, had invented a novel method to describe the behavior of electrons and photons (and their antimatter equivalent, positrons). George Johnson, SFChronicle.com, 29 Feb. 2020 The electron, quark, and muon, for example, are paired with the positron, antiquark, and antimuon, respectively. Sophia Chen, Wired, 19 Feb. 2020 Bananas, which contain trace amounts of radioactive potassium, emit a positron every 75 minutes. Sophia Chen, Wired, 19 Feb. 2020 By contrast, the researchers observed that some electrons and positrons seem to be correlated in their emission direction. Chris Lee, Ars Technica, 20 Dec. 2019 Positronium is a volatile, short-lived atom that seems kind of like hydrogen but has a positron—an antiparticle considered opposite to an electron, sometimes even called an antielectron—instead of a proton. Caroline Delbert, Popular Mechanics, 9 Dec. 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'positron.' 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 positron

1933, in the meaning defined above

History and Etymology for positron

positive + -tron (as in electron)

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Time Traveler for positron

Time Traveler

The first known use of positron was in 1933

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Cite this Entry

“Positron.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/positron. Accessed 23 Jun. 2021.

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English Language Learners Definition of positron

physics : a very small particle of matter that has a positive charge of electricity and that travels around the nucleus of an atom


pos·​i·​tron | \ ˈpäz-ə-ˌträn How to pronounce positron (audio) \

Medical Definition of positron

: a positively charged particle having the same mass and magnitude of charge as the electron and constituting the antiparticle of the electron

called also positive electron

More from Merriam-Webster on positron

Britannica.com: Encyclopedia article about positron


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