: 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 alsoalpha, alpha radiation, alpha ray
Example Sentences
Recent Examples on the WebThe fourth decay can occur by two different routes, with each path releasing one alpha particle and one beta particle before reaching lead-209. Jacqueline Detwiler, Popular Mechanics, 1 Feb. 2020 Starting with oxygen gas, the team will split its nucleus into a helium nucleus, also known as an alpha particle, and a carbon-12 nucleus. David Grossman, Popular Mechanics, 21 Aug. 2019 Hoyle state nuclei almost always decay right back into beryllium and an alpha particle.Quanta Magazine, 4 Dec. 2012 Like a bent arm, the Hoyle state takes the shape of an obtuse triangle with an alpha particle at each vertex.Quanta Magazine, 4 Dec. 2012 These particles, primarily composed of electrons, protons, and helium nuclei (known as alpha particles), fly all over the solar system. Jay Bennett, Popular Mechanics, 9 Aug. 2018 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, 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, 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, 24 Mar. 2018 See More