Determine the Half-life of a Substance

What is the half-life of a substance that decays from 10.4 to 3.4 in 20 hours?

A) 5.42 hours

Answer

The half-life of the substance that decays from 10.4 to 3.4 in 20 hours is approximately 5.42 hours.

The half-life of a substance refers to the time taken for half of the initial amount of the substance to decay. In this case, we are given that a substance decays from 10.4 to 3.4 in 20 hours. By using the formula for calculating half-life:

t1/2 = (ln(2) * t) / ln(A/A')

We can substitute the given values A = 10.4, A' = 3.4, and t = 20 hours into the formula:

t1/2 = (ln(2) * 20) / ln(10.4/3.4)

Calculating this expression gives us the half-life of the substance, which is approximately 5.42 hours.