alpha particle

Science Dictionary
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 © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source
Explore Dictionary.com
Previous Definition: alpha naphthol
Next Definition: alpha particles
Words Near: alpha particle
More from Thesaurus.com
Synonyms and Antonyms for alpha particle
More from Reference.com
Search for articles containing alpha particle
More from Dictionary.com Translator
Dictionary.com Word FAQs

Dictionary.com presents 366 FAQs, incorporating some of the frequently asked questions from the past with newer queries.

Copyright © 2014 Dictionary.com, LLC. All rights reserved.
  • Please Login or Sign Up to use the Recent Searches feature