[SOLVED] Radioactivity -- Why no reading on Geiger counter? 1. The problem statement, all variables and given/known data A magnet is directly between a Geiger counter and a material that is know to be radioactive. If the Geiger counter does not register any radioactivity, what kinds of particles is the radioactive substance emitting? Why doesn't the Geiger counter register any radioactivity? 2. The attempt at a solution What kind of particles? Either one of the three: Alpha, Beta, or Gamma. We can't say for certain because the magnet will definitely stop alpha and beta particles. Now since the Geiger counter doesn't register any radioactivity, .... *Kinda stuck.* Let's answer the 2nd question first. The Geiger counter doesn't register any radioactivity because the magnet placed in between the counter and the radioactive substance is evidently stopping the radioactive particles. Then now to the first question..... We cannot say for certain which of the three radioactive particles is being emitted by the substance because the magnet will definitely stop alpha and beta particles. Now since the Geiger counter is not registering any radioactivity, it's also possible that gamma rays were stopped by the magnet. Now where I need your opinion... Does my answer make sense? Is this question really that simple to answer? Do you think that the magnet can stop gamma rays? Because if it cannot, then the substance is not emitting gamma rays, because if it were, then the rays would have passed through the magnet and cause a reading on the Geiger counter. PLEASE HELP!!! Thank you!!!