Physics 2021 JAMB Past Questions - Question 30: The half – life of an element is 24 hours. What fraction of the atoms has disintegrated in 72 hours?

Correct Answer

A

Explanation

The fraction of atoms that have disintegrated after 72 hours can be calculated using the formula:

\[ \left( \frac{1}{2} \right) ^{\frac{72}{24}} = \left( \frac{1}{2} \right) ^3 = \frac{1}{8} \]

So, after 72 hours, \(\frac{1}{8}\) or 12.5% of the atoms have disintegrated.