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Gamma decay
Intermediate
Emission of high-energy photons from excited nuclei.
An excited nucleus drops to a lower state by emitting a photon of MeV energy; Z and A don't change. Very penetrating.
Cobalt-60 emits 1.17 and 1.33 MeV.
Follows alpha or beta decay.
In more detail
Gamma decay releases a high-energy photon from an excited nucleus, usually after alpha or beta decay. It does not change the mass or atomic number.
Real-world uses
- Gamma cameras in medicine detect radiation from tracers.
- Sterilisation uses gamma radiation from cobalt-60.
- Gamma rays from cobalt-60 sources are used to sterilise medical equipment and to treat cancer.
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Frequently asked questions
What causes gamma decay?
A nucleus in an excited state losing energy by emitting a photon.
Does gamma decay change the element?
No, the nucleus remains the same element and mass number.
Does gamma decay change the element?
No. The nucleus loses excess energy as a photon, without changing its number of protons or neutrons.
Related topics in Atomic & Nuclear Physics
Radioactivity discovery · Alpha decay · Beta decay · Radioactive decay law · Half-life · Mean life