Question

A human body required the 0.01 Curie activity of radioactive substance after 24 hours. A half-life of radioactive is 6 hours. The activity of the radioactive substance that can be injected will be:

• A. 0.08
• B. 0.04
• C. 0.16
• D. 0.32

Answer 1

The correct option is C 0.16

Half-life = 6 hours

No. of half lives in 24 hours = 24/6 = 4

In 24 hours, the activity will reduce by $\frac{1}{2^4}$ of the original activity.

Required activity after 24 hours = 0.01

Activity of substance that can be injected = 0.16

Option C is correct.