what type of radiation does strontium 90 emit
Strontium-90 Naturally occurring strontium is nonradioactive and nontoxic at levels normally found in the environment, but 90Sr is a radiation hazard.[3] 90Sr undergoes β− decay with a half-life of 28.79 years and a decay energy of 0.546 MeV distributed to an electron, an anti-neutrino, and the yttrium isotope 90Y, which in turn undergoes β− decay with half-life of 64 hours and decay energy 2.28 MeV distributed to an electron, an anti-neutrino, and 90Zr (zirconium), which is stable.[4] Note that 90Sr/Y is almost a pure beta particle source; the gamma photon emission from the decay of 90Y is so infrequent that it can normally be ignored.