Three radioactive particles

• Has two protons, two neutrons (equal to a helium nucleus)
• Very ionising
• This causes alpha particles to get stopped easily due to matter/substances. Therefore it has little penetrating power and can only go 5cm in air.
• Alpha can be stopped by paper.
• Alpha decay equation example:

This shows that radium loses 2 protons and 2 neutrons. Always take the mass and atomic number of an alpha atom away from the unstable element.

• A use for alpha is in smoke alarms. When smoke gets to the detector the alpha is stopped therefore the current stops flowing and sets off an alarm.

• It's a fast moving electron
• It isn't very ionising therefore it's more penetrating
• Range of 1m in air and can be stopped by aluminium
• Beta decay equation example:

This means that carbon just loses an electron. Just minus 1 from the element undergoing beta decay.

• Beta is used for measuring thickness of silver foil. The thicker the foil, the more beta particles will be absorbed.

• Just an electromagnetic wave
• Not very ionising at all
• Very penetrating
• Unlimited range
• Stopped by thick lead
• Can be used to sterilise medical equipment. Gamma rays penetrate far into the equipment, killing all pathogens.