Answer:
I. 100 Bg
II. 50 Bg
III. 25 Bg
Explanation:
I. Determination of the activity after 26 hours.
We'll begin by calculating the number of half-lives that has elapse. This can be obtained as follow:
Half-life (t½) = 13 hours
Time (t) = 26 hours
Number of half-lives (n) =?
n = t / t½
n = 26 / 13
n = 2
Finally, we shall determine remaining activity
Original activity (N₀) = 400 Bg
Number of half-lives (n) = 2
Activity remaining (N) =?
N = 1/2ⁿ × N₀
N = 1/2² × 400
N = 1/4 × 400
N = 100 Bg
II. Determination of the activity after 39 hours.
We'll begin by calculating the number of half-lives that has elapse. This can be obtained as follow:
Half-life (t½) = 13 hours
Time (t) = 39 hours
Number of half-lives (n) =?
n = t / t½
n = 39 / 13
n = 3
Finally, we shall determine remaining activity.
Original activity (N₀) = 400 Bg
Number of half-lives (n) = 3
Activity remaining (N) =?
N = 1/2ⁿ × N₀
N = 1/2³ × 400
N = 1/8 × 400
N = 50 Bg
III. Determination of the activity after 52 hours.
We'll begin by calculating the number of half-lives that has elapse. This can be obtained as follow:
Half-life (t½) = 13 hours
Time (t) = 52 hours
Number of half-lives (n) =?
n = t / t½
n = 52 / 13
n = 4
Finally, we shall determine remaining activity
Original activity (N₀) = 400 Bg
Number of half-lives (n) = 4
Activity remaining (N) =?
N = 1/2ⁿ × N₀
N = 1/2⁴ × 400
N = 1/16 × 400
N = 25 Bg
