Gamma rays are the radioactive emissions with the most penetrating power.
Explanation;
Alpha, beta particles and gamma rays are the three main types of radiations emitted by unstable or radioactive isotopes.
Gamma radiation does not consist any particles but contain a photon of energy emitted from an unstable nucleus. Gamma radiation has no charge or mass, thus can travel farther through air than the other radiations.
Gamma is the most penetrating radiation with alpha being the least penetrating.
