Chapter 2, Problem 25E

The average atomic masses of some elements may vary, depending upon the sources of their ores. Naturally occurring boron consists of two isotopes with accurately known masses ( ${}^{10}\text{B}$, 10.0129 amu and ${}^{11}\text{B}$, 11.0931 amu). The actual atomic mass of boron can vary from 10.807 to 10.8 19, depending on whether the mineral source is from Turkey or the United States. Calculate the percent abundances leading to the two values of the average atomic masses of boron from these two countries.