What is percent composition in chemistry?

Percent composition refers specifically to the mass percentage of each individual element within a compound. This concept is essential in stoichiometry, as it allows chemists to determine how much of each element is present in a given sample of a compound.

To calculate the percent composition, you take the mass of each element in the compound and divide it by the total mass of the compound, then multiply by 100 to convert it to a percentage. For example, in water (H₂O), the percent composition for hydrogen and oxygen can be calculated based on their respective atomic masses and the total mass of the compound. This type of analysis is crucial in understanding chemical formulas and reactions.

The other choices do not accurately define percent composition. While total weight, ratios, and volumes may relate to the broader study of compounds, they do not specifically address the mass percentage aspect that is central to percent composition.