A radioactive element has a half life of 4 days. The frac...
A radioactive element has a half life of 4 days. The fraction that has decayed in 16 days is?
(15)/16
(1)/16
(3)/4
(1)/4
Correct answer is B
16 days = 4 half lives.
The fraction left 16 days = after 4 half live, = (1/2)4 = (1)/16.