Question:List the penetrating power and ionising power of the three nuclear radiation in a table.
|Radiation||Penetration ability||Ionisation ability||Stopped by|
|Alpha||Least||Greatest||Paper or 5cm of air|
|Beta||Medium||Medium||5 mm of aluminium or 5 meters of air|
|Gamma||Highest||Lowest||Intensity reduced to 1/2 by metres of lead|
NB The more penetrating, the less ionising. Ionisation requires energy, the more ionisations that are produced, the more quickly the particle loses energy and the less distance it can travel.
It is a common misconception to believe that alpha particles are relatively harmless because they can be stopped by a piece of paper. However, they have done much more damage to the paper in being stopped than the beta particles did by passing through.