beta particle

noun

: a high-speed electron
specifically : one emitted by a radioactive nucleus in beta decay

Examples of beta particle in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Soon thereafter, beta particles were identified as electrons, bringing these two independent aspects of reality together. Ethan Siegel, Big Think, 30 Sep. 2025 As a result of these reactions, beta particles are emitted at such high energy that their velocity exceeds the speed of light in water. Abhishek Bhardwaj, Interesting Engineering, 9 Sep. 2025 The decay of the radioisotope produces high-energy beta particles that ionize the electrolyte, creating a potential difference between the anode and cathode immersed in the solution and driving electron flow through an external circuit to produce electricity. IEEE Spectrum, 25 Aug. 2025 The beta particles emitted from carbon-14 are already present in nearly everything, including naturally in the human body. Joe Salas, New Atlas, 26 Mar. 2025 The primary emission consists of beta particles, high-energy electrons capable of penetrating tumors and surrounding cells, tearing into DNA and causing damage that ultimately triggers cell death. Discover Magazine, 8 July 2024

Word History

First Known Use

1904, in the meaning defined above

Time Traveler
The first known use of beta particle was in 1904

Browse Nearby Words

Cite this Entry

“Beta particle.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/beta%20particle. Accessed 4 Jul. 2026.

Kids Definition

beta particle

noun
: an electron or positron that is thrown out from the nucleus of an atom during radioactive decay
also : a high-speed electron or positron

Medical Definition

beta particle

noun
: a high-speed electron
specifically : one emitted during radioactive decay of an atomic nucleus

More from Merriam-Webster on beta particle

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

More from Merriam-Webster