Dictionary.com

alpha particle

Save This Word!

noun Physics.
a positively charged particle consisting of two protons and two neutrons, emitted in radioactive decay or nuclear fission; the nucleus of a helium atom.
QUIZ
GOOSES. GEESES. I WANT THIS QUIZ ON PLURAL NOUNS!
Test how much you really know about regular and irregular plural nouns with this quiz.
Question 1 of 9
Which of the following nouns has an irregular plural form?

Origin of alpha particle

First recorded in 1900–05
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2022

How to use alpha particle in a sentence

British Dictionary definitions for alpha particle

alpha particle

noun
a helium-4 nucleus, containing two neutrons and two protons, emitted during some radioactive transformations
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medical definitions for alpha particle

alpha particle

n.
A positively charged nuclear particle, indistinguishable from a helium atom nucleus and consisting of two protons and two neutrons.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Scientific definitions for alpha particle

alpha particle

A positively charged particle that consists of two protons and two neutrons bound together. It is emitted by an atomic nucleus undergoing radioactive decay and is identical to the nucleus of a helium atom. Because of their relatively large mass, alpha particles are the slowest and least penetrating forms of nuclear radiation. They can be stopped by a piece of paper. See more at radioactive decay.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
FEEDBACK