5. How does the abundance of isotopes of an element relate to its average atomic mass?

The average atomic mass of an element is the mass you see on a periodic table for that element. It is a weighted average of all the isotopes for that element based on the percentage of how much of an element is a specific isotope and the mass of each isotope. If an element has an abundance of isotopes, the isotopes with the highest and lowest masses may be more significantly different than the average atomic mass for elements with fewer isotopes.