Which term is used to refer to the average mass of the atoms of an element based on the relative abundance of its isotopes?

Which term is used to refer to the average mass of the atoms of an element based on the relative abundance of its isotopes?

• A. Molecular mass
• B. Atomic weight
• C. Atomic mass
• D. Isotopic mass

Answer: (C)

The term that refers to the average mass of the atoms of an element, considering the relative abundance of its isotopes, is atomic weight. Atomic weight is a weighted average that reflects the proportions of each isotope found in nature, which means it takes into account both the mass of each isotope and its occurrence. In contrast, atomic mass typically refers to the mass of a specific isotope of an element, while molecular mass is related to the mass of a molecule—calculated by adding the atomic masses of its constituent atoms. Isotopic mass refers to the mass of a specific isotope alone, without consideration for its abundance among other isotopes of the same element. Thus, while atomic mass, molecular mass, and isotopic mass each have their distinct definitions, atomic weight is the correct term for the average mass calculated from all isotopes of an element in their natural proportions.

The term that refers to the average mass of the atoms of an element, considering the relative abundance of its isotopes, is atomic weight. Atomic weight is a weighted average that reflects the proportions of each isotope found in nature, which means it takes into account both the mass of each isotope and its occurrence.

In contrast, atomic mass typically refers to the mass of a specific isotope of an element, while molecular mass is related to the mass of a molecule—calculated by adding the atomic masses of its constituent atoms. Isotopic mass refers to the mass of a specific isotope alone, without consideration for its abundance among other isotopes of the same element. Thus, while atomic mass, molecular mass, and isotopic mass each have their distinct definitions, atomic weight is the correct term for the average mass calculated from all isotopes of an element in their natural proportions.