Question

If the activity of a radionuclide decreases from 5,000 disintegrations per minute to 625 disintegrations per minute

in 12 hours, its half-life is?

Answer 1

4 hrs

Step-by-step explanation:

625 = 5000 (1/2)^n

625/5000 = 1/2^n

n = 3 half lives

3 half lives = 12 hours 1 half life = 4 hrs