Answer:
2.7
Explanation:
This can be modeled using exponential growth/decay.
A = P (1 + r)ⁿ
where A is the final amount,
P is the initial amount,
r is the rate of growth/decay,
and n is the number of cycles.
For half life problems, r = -½, and n = t / T, where t is time and T is the half life.
A = P (1 − ½)^(t/T)
A = P (½)^(t/T)
Given that P = 9, t = 10000, and T = 5730:
A = 9 (½)^(10000/5730)
A ≈ 2.7
There are approximately 2.7 mg of ¹⁴C left.