What fraction of radioactive atoms remains in a sample after five half-lives

Question

Quizplus · Accepted Answer

After each half-life, the number of radioactive atoms in the sample is reduced by half. After one half-life, half of the atoms remain; after two half-lives, one-quarter (1/2 x 1/2) remain; after three half-lives, one-eighth (1/2 x 1/2 x 1/2) remain; after four half-lives, one-sixteenth (1/2 x 1/2 x 1/2 x 1/2) remain; and after five half-lives, one-thirty-second (1/2 x 1/2 x 1/2 x 1/2 x 1/2) remain. Therefore, the fraction of radioactive atoms that remains after five half-lives is 1/32.

What Fraction of Radioactive Atoms Remains in a Sample After