R1A1D2I1O1A1C3T1I1V4I1T1I1E1S1
21 points
RADIOACTIVITIES is validvalid
RADIOACTIVITY, the quality of being radioactive
RADIOACTIVITY, the spontaneous decay of the nucleus of an element
RADIOACTIVITY, the quality of being radioactive
RADIOACTIVITY, the spontaneous decay of the nucleus of an element