Nuclear Physics And Radioactivity Question 375
Question: A radioactive substance has an average life of 5 hours. In a time of 5 hours [Orissa JEE 2003]
Options:
A) Half of the active nuclei decay
B) Less than half of the active nuclei decay
C) More than half of the active nuclei decay
D) All active nuclei decay
Show Answer
Answer:
Correct Answer: C
Solution:
If $ \lambda $ is the decay constant of a radioactive substance than average life = $ \frac{1}{\lambda } $ Also half life $ =\frac{0.693}{\lambda }=0.693\times (Average\ life) $ in single average life, more than 63% of radioactive nuclei decay
BETA
