Question

How many half-lives does Carbon-10 undergo in 2 minutes and 32 seconds? Given the half-life of Carbon-10 is about 19 seconds.

• A. 8 half-lives
• B. 7 half-lives
• C. 6 half-lives
• D. 5 half-lives
• E. 4 half-lives

Answer 1

The correct option is A 8 half-lives

Given : $T_{1/2}=19$ sec

Time of observation, $t=2$ min and $32$ sec $=152$ sec

Thus number of half lives, $n=\frac{t}{T_{1/2}}=\frac{152}{19}=8$ half-lives