Half life graph from Kinsey’s
Richard Taylor (The Hockaday School, Dallas, TX) has a cat (Kinsey) that needed radiation treatment for feline hyperthyroidism. Richard used our Student Radiation Monitor, LabPro, and a TI-84 to monitor the radiation from Kinsey over several days. Kinsey was injected with I-131, which has a half life of about five days. The count rated dropped off faster than the half life would imply, but Richard noted that the litter box was also very radioactive. Also note that Kinsey was more radioactive by a factor or 10 or so than anything you would ever buy for use in a science classroom.