Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Radioacivity questions!

  1. Nov 24, 2006 #1
    Here is my question from lab:

    In an experiment, you will use cardboard, copper foil, aluminum plate and lead sheet to block β particles. If you had equal thicknesses of each substance, which would be most effective blocker? Which would be the least effective blocker?

    I think that the cardboard would be the least effiective and the lead the most effictive. I believe that both copper and aluminum will stop the Beta particles, however my book says "beta particles can penetrate a few mm of aluminum".... does that mean alumimum can stop them too? Thanks in advance!
  2. jcsd
  3. Nov 24, 2006 #2


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    They all stop beta particles to a certain extent but some materials are better at stopping them than others. If you had thick enough cardboard you could stop them completely, but it would be a lot thicker than the amount of lead you'd have to use for the same effect.
  4. Nov 25, 2006 #3


    User Avatar
    Staff Emeritus
    Science Advisor

    Ionizing radiation, as the name implies, interacts predominantly with the electrons in the atoms of the material through which it passes. The most effective shielding materials are those with the highest electron densities. Some amount of energy is lost through interaction with the nuclei (e.g. brehmsstrahlung radiation).
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook