Tritium has a half-life of 12.3 years.How many years will elapse when the radioactivity of a tritium sample diminishes to 35% of its original value?
A)1.2E-1 years
B)1.9E+1 years
C)4.3E+0 years
D)6.3E+1 years
E)8.1E+0 years

Question

Tritium has a half-life of 12.3 years.How many years will elapse when the radioactivity of a tritium sample diminishes to 35% of its original value?
A)1.2E-1 years
B)1.9E+1 years
C)4.3E+0 years
D)6.3E+1 years
E)​8.1E+0 years

Quizplus · Accepted Answer

The half-life formula is used to calculate the time it takes for a quantity to reduce to half its initial value. The formula is $ t = \frac{\ln(\frac{final\ amount}{initial\ amount})}{\ln(0.5)} \times half\ life $. Substituting the given values, $ t = \frac{\ln(0.35)}{\ln(0.5)} \times 12.3 $ years, which calculates to approximately 19 years.

Tritium Has a Half-Life of 12