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Summary of different types of radiation




Properties of ionizing radiation

Name
Source
Nature
Charge
Penetrating power
Alpha (a) particles
Radioactive decay
A helium nucleus
2+
A sheet of paper or the outer layer of skin can stop a particles.
Beta (b) particles
Radioactive decay
An electron
1-
A sheet of aluminium a few millimeters thick can stop b particles
Neutrons
Nuclear reactor
A neutron
Nil
Hydrogen-rich materials, such as paraffin or water, can stop neutrons.
Gamma (g) rays
Radioactive decay
High energy electromagnetic wave
Nil
High density materials, such as thick barriers of concrete, can stop g rays.
X-rays
Electron excitation
High energy electromagnetic wave
Nil
High density materials, such as thick barriers of concrete, can stop x-rays.



Common types of radionuclides

Radionuclide
Atomic number
a particles
b particles
g rays
Tritium
1
 
 
Cobalt-60
27
 
Strontium-90
38
 
 
Technetium-99
43
 
 
Iodine-131
53
 
Cesium-137
55
 
Radon-222
86
 
Radium-226
88
 
Thorium-232
90
 
Uranium-238
92
 
Plutonium-236
94
 
Americium-241
95