Final answer:
The relationship between percent composition and average atomic mass is that the percent composition is directly related to the atomic mass of an element.
Step-by-step explanation:
The relationship between percent composition and average atomic mass can be understood by looking at the calculation of the percent composition of a compound. Percent composition tells us what percent of the total mass of a compound arises from each element in the compound. When calculating the percent composition, we divide the atomic mass of the element by the molar mass of the molecule. Therefore, the percent composition is directly related to the atomic mass of the element.