Name
Symbols
Identity
Relative Charge
Relative Mass
Penetrating Power
Interaction with Charged Plates
Hazards
alpha
,
42He
helium
nucleus
2+
4
low - stopped by a sheet of paper
attracted to negative plate, deflected by positive plate
harmful if ingested
beta
,
0-1e
electron
1-
1
2000
moderate - pass through paper and ½mm aluminium, stopped by ½mm lead
attracted to positive plate, deflected by negative plate
skin burns, harmful if ingested, particularly iodine-131 in thyroid &
strontium-90 in bones
gamma

electro-
magnetic
radiation
0
0
high - only stopped by several centimetres of lead or many centimetres of
concrete
unaffected
most dangerous as these are the most penetrating, as a consequence, gamma
rays can be used to sterilize materials & destroy bacteria in food