Which three types of information are required to calculate the average atomic mass of an element?

• A. The masses of each isotope, the natural abundances of each isotope, and the identity of each isotope
• B. The masses of each isotope, the natural abundances of each isotope, and the number of protons in each isotope
• C. The masses of each isotope, the natural abundances of each isotope, and the number of neutrons in each isotope
• D. The atomic number, the mass number, and the electron configuration of the element

Answer: (A)

Verified step by step guidance

1. Understand that the average atomic mass of an element is a weighted average of the masses of its naturally occurring isotopes.
2. Identify that to calculate this average, you need the mass of each isotope because each isotope has a different mass.
3. Recognize that the natural abundance of each isotope is required to know how much each isotope contributes to the average mass.
4. Note that the identity of each isotope (which isotope it is) is important to correctly associate each mass with its corresponding abundance.
5. Conclude that information like the number of protons, neutrons, atomic number, or electron configuration is not directly needed for calculating the average atomic mass.