Penetrating very short-wavelength electromagnetic radiation, similar to an X-ray but of higher energy, that is emitted spontaneously by some radioactive substances (&see; gamma decay; radioactivity).
Gamma radiation also originates in the decay of certain subatomic particles and in particle-antiparticle annihilation (&seealso; antimatter). Gamma rays can initiate nuclear fission, can be absorbed by ejection of an electron (&see; photoelectric effect), and can be scattered by free electrons (&see; Compton effect).
This is the complete article, containing 69 words
(approx. 1 page at 300 words per page).
View More Summaries on Gamma ray
