The half-life of ²¹⁸Po is 3.1 minutes. How much of a 155 gram sample remains after 0.40 hours?

Question

Quizplus · Accepted Answer

First, we need to convert 0.40 hours into minutes:

0.40 hours * 60 = 24 minutes

Now we can use the half-life formula:

N(t) = N0(1/2)^(t/T)

where:
N0 = initial amount
N(t) = amount remaining after time t
T = half-life

We know that T = 3.1 minutes and N0 = 155 grams. So for t = 24 minutes:

N(24) = 155*(1/2)^(24/3.1) = 0.72 grams

Therefore, 0.72 grams of the sample remains after 0.40 hours, which is answer choice C.

The Half-Life of 218Po Is 3