Question

Potassium-42 has a half-life of 12.4 hours. How much of a 745 g sample will be left after 74.4 hours?

A. 11.6 g
B. 22.2 g
C. 44.4 g
D. 88.8 g

Answer 1

Approximately 22.2 g of the 745 g sample of Potassium-42 will be left after 74.4 hours.

Step-by-step explanation:

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

N = N0 × (1/2)^(t/h)

Where N is the amount remaining, N0 is the initial amount, t is the time elapsed, and h is the half-life.

Given that the initial amount is 745 g and the half-life is 12.4 hours, we can plug these values into the formula:

N = 745 × (1/2)^(74.4/12.4)

Calculating this expression, we find that approximately 22.2 g will be left after 74.4 hours.