Answer:
6.25 g
Step-by-step explanation:
Concept: Half life
What is half life?
- Half life is the time taken by a radioactive substance to decay by half of its original mass.
In this case;
Half life of Plutonium-239 is 24,110 years
Original mass of plutonium-239 is 100 g
Time for the decay is 96,440 years
We are required to calculate the remaining mass;
Using the formula;
Remaining mass = Original mass × 0.5^n
where n is the number of half lives
n = Time ÷ Half life
= 96,440 yrs ÷24,110 years
= 4
Therefore;
Remaining mass = 100 g × 0.5^4
= 6.25 g
Thus, the mass of plutonium-239 that will remain after 96,440 years will be 6.25 g