Nuclear Chemistry Question 9

Question: The half-life of 1 gm of radioactive sample is 9 hours. The radioactive decay obeys first order kinetics. The time required for the original sample to reduce to 0.2 gm is

[AMU (Engg.) 2002]

Options:

A) 15.6 hours

B) 156 hours

C) 20.9 hours

D) 2.09 hours

Show Answer

Answer:

Correct Answer: C

Solution:

$ \frac{0.693}{9}=\frac{2.303}{t}\log \frac{1}{1-0.2} $