Percentage composition by mass is calculated using which formula?

The formula for calculating percentage composition by mass involves determining the contribution of a specific element to the total mass of a compound. The correct formula takes the relative atomic mass of the element multiplied by the number of moles of that element in the compound. This product gives the total mass of the element in the compound.

By dividing this total mass of the element by the molar mass of the entire compound, and then multiplying by 100, you arrive at the percentage composition by mass of that element. This method effectively quantifies how much of the compound's total mass is attributed to that specific element, thus providing a clear understanding of its abundance in the compound.

The other options fail to accurately represent this relationship or include incorrect components, leading to either incomplete calculations or irrelevant information for determining percentage composition by mass.