If the age of the Earth is 4.5 billion years and the half-life of ⁴⁰K is 1.26 billion years,what percent of the Earth's original amount of ⁴⁰K remains today?

Question

Quizplus · Accepted Answer

The formula for determining the percent of remaining substance after a certain amount of time has passed using half-life is:

Percent Remaining = (1/2)^(total time passed / half-life) x 100%

Plugging in the values given:

Percent Remaining = (1/2)^(4.5/1.26) x 100%
Percent Remaining = 0.084 x 100%
Percent Remaining = 8.4%

Therefore, the best choice is B) 8.4%.

If the Age of the Earth Is 4