Practice question

Activity defines number of nuclear transformations per second. Early radium studies led to curie originally defined as activity of one gram radium-226, experimentally measured as 3.7 times ten to tenth disintegrations per second. Becquerel later adopted as SI unit equals one disintegration per second, so curie equals 37 gigabecquerel. Sievert and gray describe dose, not decay rate. Understanding curie allows conversion between historical literature and modern tracer preparation, determining amounts of phosphorus-32 or iodine-125 required for labeling experiments while maintaining safety limits.