JAMB - Physics (2006 - No. 29)
A radioactive element has a half life of 4 days. The fraction that has decayed in 16 days is?
\(\frac{15}{16}\)
\(\frac{1}{16}\)
\(\frac{3}{4}\)
\(\frac{1}{4}\)
Forklaring
16 days = 4 half-lives.
The fraction left 16 days = after 4 half live, = (1/2)4 = (1)/16
Fraction that decayed = 1- \(\frac{1}{16}\)
\(\frac{15}{16}\)