beta particle

American  

noun

Physics.

1. an electron or positron emitted from an atomic nucleus in a certain type of radioactive decay.

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beta particle British  

noun

1. a high-speed electron or positron emitted by a nucleus during radioactive decay or nuclear fission

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beta particle Scientific  

1. A high-speed electron or positron, usually emitted by an atomic nucleus undergoing radioactive decay. Beta particles are given off naturally by decaying neutrons in radioactive atoms and can be created in particle accelerators. Beta particles have greater speed and penetrating power than alpha particles but can be stopped by a sheet of aluminum that is 2 to 3 mm thick.

2. See more at radioactive decay

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Etymology

Origin of beta particle

First recorded in 1900–05

Example Sentences

Tritium gives off only low-energy beta particles believed to pose minimal risks for marine life and humans.

From Science Magazine

They enforced a safety perimeter around the reactor and suffered burns from beta particles in the radioactive dust.

From Science Magazine

Because tritium emits only low-energy beta particles, it poses a modest health risk.

From Science Magazine

Because it gives off only low-energy beta particles, tritium poses a modest health risk.

From Science Magazine

Cesium emits two types of radiation - beta particles and gamma rays- that have enough energy to damage human tissue.

From Washington Times