Answer :
Answer:
[tex]\huge\boxed{\sf 0.03\ kg}[/tex]
Explanation:
Half Life of Ca-137 = 30.2 years
Time duration = 151 years
Initial mass = 1 kg
Number of half lives:
To find the number of half lives, we will divide the actual time duration by the half life of Cs.
So,
= Time duration/half life
= 151/30.2
= 5 half lives
This means, 5 half lives have passed.
Half life:
- The time in which half of the original quantity is decayed and half is left.
So, the amount of Cs after:
1 half life:
= 1/2
= 0.5 kg
2 half lives:
= 0.5/2
= 0.25 kg
3 half lives:
= 0.25/2
= 0.125 kg
4 half lives:
= 0.125/2
= 0.0625 kg
5 half lives:
= 0.0625/2
= 0.03 kg
[tex]\rule[225]{225}{2}[/tex]