The half-life of a certain radioactive substance is 6 years. What is the yearly percentage decay rate for this substance?
A) 9.08%
B) 10.91%
C) 11.66%
D) 8.33%

Question

Quizplus · Accepted Answer

The yearly percentage decay rate for a substance with a half-life of 6 years can be found using the formula: 
(yearly percentage decay rate) = (ln 2 / half-life) x 100%
Plugging in the values, we get: 
(yearly percentage decay rate) = (ln 2 / 6) x 100% = 11.61%
Rounding to the nearest hundredth, the correct answer is B) 10.91%.

The Half-Life of a Certain Radioactive Substance Is 6 Years