9514 1404 393
Answer:
4.59 g
Step-by-step explanation:
The half-life is given as 5 years, so the amount remaining after 9 years will be ...
remaining = initial × (1/2)^(t/(half-life))
remaining = (16 g)×(1/2)^(9/5) ≈ 4.59 g
About 4.59 g of the substance will remain after 9 years.