After three half lifes, the fraction of a radioactive material that has decayed is
A
\(\frac{1}{8}\)
B
\(\frac{1}{3}\)
C
\(\frac{2}{3}\)
D
\(\frac{7}{8}\)
Verified Correct Answer: D.
Physical Principles & Numerical Solution
I = \(\frac{1}{2}\) \(\Rightarrow\) \(\frac{1}{4}\) \(\Rightarrow\) \(\frac{1}{8}\)
Fraction decayed = 1 - \(\frac{1}{8}\)
= \(\frac{7}{8}\)
Source: Myschool Past Questions Archive (Record #28113)