alpha decay

American  

noun

Physics.

1. a radioactive process in which an alpha particle is emitted from the nucleus of an atom, decreasing its atomic number by two.

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alpha decay British  

noun

1. the radioactive decay process resulting in emission of alpha particles

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alpha decay Scientific  

1. The radioactive decay of an atomic nucleus by emission of an alpha particle (two protons bound to two neutrons). When an element undergoes alpha decay, its atomic number decreases by two.

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Etymology

Origin of alpha decay

First recorded in 1935–40

Example Sentences

Unlike many other isotopes, At-211 does not produce harmful secondary alpha decay, ensuring that its energy is used efficiently for therapy.

From Science Daily • Nov. 11, 2025

Gamow performed a quick calculation using quantum rules and solved the alpha decay problem overnight, sharing his results with Hungarian physicist Eugene Wigner the next day.

From Scientific American • Aug. 18, 2021

This also happens to be the nucleus of a helium atom; helium gas may get trapped in the crystal lattice of a mineral in which alpha decay has taken place.

From Textbooks • Jan. 1, 2017

What do the three types of beta decay have in common that is distinctly different from alpha decay?

From Textbooks • Aug. 12, 2015

It just gets hot from alpha decay and generates electricity.

From Slate • Aug. 6, 2012