Nuclear Physics And Radioactivity Question 383
Question: The half-life of radium is about 1600 years. Of 100 g of radium existing now, 25 g will remain unchanged after [CBSE PMT 2004]
Options:
A) 2400 years
B) 3200 years
C) 4800 years
D) 6400 years
Show Answer
Answer:
Correct Answer: B
Solution:
$ M=M_{0}{{( \frac{1}{2} )}^{\frac{t}{{T_{1/2}}}}} $
$ \Rightarrow 25=100{{( \frac{1}{2} )}^{\frac{t}{1600}}} $
Þ t= 3200 years.
BETA
