A radioactive substance has a half life of 20 days. What fraction of the original radioactive nuclei will remain after 80 days?
Correct Option:
B
80 days = 4 half lives (i.e 4 x 20dqs = 80dq)
But the fraction always left by any radioactive material after 4 half lives is
\( \left ( \frac{1}{2} \right)^2 = \frac{1}{16} \)
But the fraction always left by any radioactive material after 4 half lives is
\( \left ( \frac{1}{2} \right)^2 = \frac{1}{16} \)