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RADIATION AND
RADIOACTIVITY
Beta Particles
Beta particle emission occurs when the
ratio of neutrons to protons is too high.
An excess neutron transforms into a
proton and electron. The proton
remains in the nucleus and the electron
is ejected. This process causes
radioactive decay of the atom. Some
beta emitters can also produce gamma
rays along with the beta emissions.
This energy is in the form of a gamma
photon. Beta particles can travel up to
several feet (meters) in open air, they
are, however, easily stopped by solid
objects.
Common Beta Emitters
Energy (MeV)
Carbon-14
0.159
Cesium-137*
0.51
Iodine-131*
0.6
Phosphorus-32
1.71
Sulfur-35 0.16
Strontium-90
0.54
Tritium (Hydrogen 3)
0.018
*Also decays by gamma emissions. Refer to
Gamma Rays and X-Rays section.
