Two radioactivity experiments, using KCI as the source, are recommended for pupils’ project investigation: (1) The mass absorption coefficient of β-particles for four different substances were determined and compared with an empirical formula. (2) The half-life of 40K was determined from the count-rate. Possibilities for improvement are discussed.

This content is only available via PDF.
AAPT members receive access to The Physics Teacher and the American Journal of Physics as a member benefit. To learn more about this member benefit and becoming an AAPT member, visit the Joining AAPT page.