**[Miss part one? Check out Atomic Mass Calculations I.]**

**[Download the accompanying PDF worksheet.]**

1. Magnesium has three naturally occurring isotopes, ^{24}Mg (78.99%, 23.9850 amu), ^{25}Mg (10.00%, 24.9858 amu), and ^{26}Mg. Determine the percent abundance and isotopic mass of ^{26}Mg.

2. Boron has two naturally occurring isotopes. Find the percent abundances of ^{10}B and ^{11}B given the isotopic mass of ^{10}B = 10.0129 amu and the isotopic mass of ^{11}B = 11.0093 amu.

3. Chlorine has two naturally occurring isotopes, ^{35}Cl (34.9689 amu) and ^{37}Cl (36.9659 amu). If chlorine has an average atomic mass of 35.4527 amu, what is the percent abundance of each isotope?