Answer:
125 g
Explanation:
The following data were obtained from the question:
Half-life (t½) = 5.3 years.
Original amount (N₀) = 1000 g
Time (t) = 15.9 years.
Amount remaining (N) =?
Next, we shall determine the number of half-lives that has elapsed. This can be obtained as follow:
Half-life (t½) = 5.3 years.
Time (t) = 15.9 years.
Number of half-lives (n) =?
n = t / t½
n = 15.9 / 5.3
n = 3
Thus, 3 half-lives has elapsed.
Finally, we shall determine the amount of Co–60 that is remaining. This can be obtained as follow:
Original amount (N₀) = 1000 g
Number of half-lives (n) = 3
Amount remaining (N) =?
N = 1/2ⁿ × N₀
N = 1/2³ × 1000
N = 1/8 × 1000
N = 0.125 × 1000
N = 125 g
Therefore, the amount of Co–60 that is remaining is 125 g
