If the amount of a radioactive element decreases from 19.2 g to 0.30 g in 12. days, what is its half-life? Be sure your answer has the correct number of

significant figures.

day(s) in one half-life

X

1 answer

The formula for calculating half-life is:

half-life = (t * ln(2)) / ln(initial amount/final amount)

Where:
t = time interval (12 days)
ln = natural logarithm

Plugging in the values:

half-life = (12 * ln(2)) / ln(19.2 / 0.30)
half-life = (12 * 0.6931) / ln(64)

Using a calculator to solve the natural logarithm:

half-life = 8.3172 / 4.1588
half-life = 1.9997

Therefore, the half-life of the radioactive element is approximately 2 days.