In the discussion, the impact of a magnet on different types of radiation emitted by radioactive substances is analyzed. Alpha particles, being charged helium nuclei, are susceptible to magnetic fields and can be deflected, potentially preventing detection by a Geiger counter. Beta particles, which are high-speed electrons, are also charged but less affected due to their velocity. Gamma particles, being neutral photons, are not influenced by magnetic fields at all. The conclusion suggests that if no radioactivity is detected, it is likely due to the magnet's interaction with alpha particles.