alpha particle

noun

: 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

These fusion products may fuse with other deuterons, creating an alpha particle, or with another helium-3 or hydrogen-3 nucleus. —Bayarbadrakh Baramsai, IEEE Spectrum, 27 Feb. 2022

Compared to beta particles, alpha particles are larger and more energetic. —Discover Magazine, 8 July 2024

Another key advantage of alpha particles is their limited travel distance. —Discover Magazine, 8 July 2024

The most common forms occur when an unstable nucleus spits out an alpha particle, consisting of two neutrons and two protons, a beta particle consisting of an energetic positron or electron, or a gamma ray, consisting of a high energy photon. —The Physics Arxiv Blog, Discover Magazine, 27 Feb. 2024

Word History

First Known Use

1903, in the meaning defined above

Kids Definition

alpha particle

noun

: a positively charged particle that is identical with the nucleus of a helium atom, consists of 2 protons and 2 neutrons, and is thrown at high speed from a radioactive atomic nucleus

Medical Definition

alpha particle

noun

: 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