Question

If $2.0 \,g$ of a radioactive isotope has a half-life of $20\, h$, the half-life of $0.25 \,g$ of the same substance is:

• A. 20 h
• B. 80 h
• C. 5 h
• D. 10 h

Answer 1

Answer: (A)

20 h

Answer 2

The half-life of the radioactive substance is independent of the amount hence, the half-life remains same i. e.,$20\, h.$