alpha particle

noun

Definition of alpha particle 

: a positively charged nuclear particle identical with the nucleus of a helium atom that consists of two protons and two neutrons and is ejected at high speed in certain radioactive transformations

called also alpha, alpha radiation, alpha ray

Examples of alpha particle in a Sentence

Recent Examples on the Web

But unlike cosmic radiation or radon gas, plutonium can lodge itself inside the body and deliver tissue-damaging alpha particles over a lifetime. Ted Sickinger, OregonLive.com, "Police looking for shooter after one injured in Keizer," 22 Apr. 2018 But unlike cosmic radiation or radon gas, plutonium can lodge itself inside the body and deliver tissue damaging alpha particles over a lifetime. Ralph Vartabedian, latimes.com, "Blowing in the wind: Plutonium at former nuclear weapons site," 16 Apr. 2018 Polonium-210 has a half-life of 139 days, meaning after this time half of its atoms have emitted an alpha particle and decayed into polonium-206 atoms. Vera Thoss, Washington Post, "How the nerve agent in the spy attack and other toxins cause widespread contamination," 24 Mar. 2018 Polonium-210 has a half life of 139 days, meaning after this time half of its atoms have emitted an alpha particle and decayed into polonium-206 atoms. Vera Thoss, Smithsonian, "How to Calculate the Danger of a Toxic Chemical to the Public," 15 Mar. 2018

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

1903, in the meaning defined above

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Phrases Related to alpha particle

alpha male

the alpha and omega

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Time Traveler for alpha particle

The first known use of alpha particle was in 1903

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More Definitions for alpha particle

alpha particle

noun

Medical Definition of alpha particle 

: a positively charged nuclear particle identical with the nucleus of a helium atom that consists of two protons and two neutrons and is ejected at high speed in certain radioactive transformations

called also alpha, alpha ray

More from Merriam-Webster on alpha particle

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Britannica.com: Encyclopedia article about alpha particle

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