Question

half life worksheet answer key 3. What percent of a sample As-81 remains un-decayed after 43.2 seconds

Answer 1

The final mass after decay can be obtained by using under given relation:

half life period of As-81 = 33 seconds

mf = mi x (1/2^n)

= 100 x ( 1/2^(43.2/33))

= 40.4 %