Question

A sample of Bismuth-212 has a mass of 2.64 grams (g) after 121 seconds (s). What was the initial mass of the sample if Bismuth-212 has a half-life of 60.5 s?
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1 point
0.66 g
1.32 g
5.28 g
10.56 g

Answer 1

To solve this problem, we can use the exponential decay formula:

Final mass = Initial mass * (1/2)^(time/half-life)

Plugging in the values we know:

2.64 g = Initial mass * (1/2)^(121/60.5)

2.64 g = Initial mass * (1/2)^2

2.64 g = Initial mass * 1/4

Initial mass = 2.64 g * 4

Initial mass = 10.56 g

Therefore, the initial mass of the sample was 10.56 grams.

Answer: 10.56 g