half lives

What Is The Fraction Equivalent Of 3 Half-lives? half-lives exponent fraction two 1/22 1/4 three1/231/8 four 1/24 1/16 five 1/25 1/32 What is the fraction of 3 half lives? Three half lives corresponds to (12)3 . So a 18 quantity of the original isotope is retained. What fraction of a sample is left after 3