give me answer in 10 min I will rate for sure . what is the likelyhood an atom of Sr-90 will decay per year? and per seconds? 2. Tc-99m is produced in a lab, a patient requires 20mCi of it, 72 hrs have passed between the production and injection, how much Tc-99m will be needed so that 20 mCi is present after 72hrs? pls answer both questions