radioactivity: Beta Radiation

Beta rays are more penetrating than alpha rays, move at a very high speed, and are deflected considerably by a magnetic field in a direction that indicates a negative charge; analysis shows that beta rays are high-speed electrons (see beta particle; electron). In beta decay a neutron within the nucleus changes to a proton, in the process emitting an electron and an antineutrino (the antiparticle of the neutrino, a neutral particle with a small mass). The electron is immediately ejected from the nucleus, and the net result is an increase of 1 in the atomic number of the nucleus but no change in the mass number. The thorium-234 produced above experiences two successive beta decays:CE5

Sections in this article:

• Introduction
• Discovery of Radioactivity
• Radioactive Disintegration Series
• Half-Life of an Element
• Radioactive Decay
• Gamma Radiation
• Beta Radiation
• Alpha Radiation
• Radioactive Emissions
• Bibliography

The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2024, Columbia University Press. All rights reserved.

See more Encyclopedia articles on: Physics