alpha particle

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alpha particle

n.
A positively charged subatomic particle, composed of two protons and two neutrons, identical with the nucleus of the helium isotope He-4.

alpha particle

n
(General Physics) a helium-4 nucleus, containing two neutrons and two protons, emitted during some radioactive transformations

al′pha par`ticle


n.
a positively charged particle consisting of two protons and two neutrons, emitted in radioactive decay or nuclear fission; the nucleus of a helium atom.
[1900–05]

alpha particle

A positively charged particle that consists of two protons and two neutrons bound together. It is emitted by the nucleus of some elements undergoing radioactive decay and is identical to the nucleus of a helium atom. Alpha particles are the slowest and least penetrating forms of nuclear radiation. ♦ The process by which a radioactive element emits an alpha particle is called alpha decay. Alpha decay results in the atomic number of the atom being decreased by two and the mass number being decreased by four. See more at radiation, radioactive decay.

alpha particle

A helium nucleus that has a positive electric charge.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.alpha particle - a positively charged particle that is the nucleus of the helium atomalpha particle - a positively charged particle that is the nucleus of the helium atom; emitted from natural or radioactive isotopes
subatomic particle, particle - a body having finite mass and internal structure but negligible dimensions
References in periodicals archive ?
Regular changes in the fine structure of histograms revealed in the experiments with collimators which isolate beams of alpha-particles flying at certain directions.
First, the scroll fragments were bombarded with alpha-particles and X-rays from the portable XPIXE device, and then with proton beams produced by a particle accelerator.
The researchers meticulously recorded the emission of four alpha-particles, each a helium nucleus with two protons and two neutrons.