Chapter 0, Problem 13PE

Practice Exercise 0.13

Naturally occurring boron is composed of 19.9% of ${}^{\text{10}}\text{B}$ atoms and 80.1% of ${}^{\text{11}}\text{B}$ atoms. Atoms of ${}^{\text{10}}\text{B}$ have a mass of 10.0129 u and those of ${}^{\text{11}}\text{B}$ have a mass of 11.0093 u. Calculate the average atomic mass of boron. (Hint: Convert percent abundance to relative abundance.)