The mass defect in nuclear binding energy implies what about the mass of a bound nucleus?

The mass defect in nuclear binding energy implies what about the mass of a bound nucleus?

• A. The bound nucleus has more mass than the sum of its parts.
• B. The bound nucleus has less mass than the sum of its parts.
• C. The masses are equal.
• D. The mass defect depends on the chemical state of the atom.

Answer: (C)

Mass defect reflects the energy released when nucleons bind together. When a nucleus forms, the strong force pulls the nucleons into a more stable configuration and release binding energy. That energy has mass equivalent via E = mc^2, so the rest mass of the bound nucleus is smaller than the sum of the masses of the individual protons and neutrons by an amount Δm = B/c^2, where B is the binding energy. In other words, the bound nucleus has less mass than the sum of its parts. This mass difference is a property of the nucleus itself and does not depend on the chemical state of the atom.

Mass defect reflects the energy released when nucleons bind together. When a nucleus forms, the strong force pulls the nucleons into a more stable configuration and release binding energy. That energy has mass equivalent via E = mc^2, so the rest mass of the bound nucleus is smaller than the sum of the masses of the individual protons and neutrons by an amount Δm = B/c^2, where B is the binding energy. In other words, the bound nucleus has less mass than the sum of its parts. This mass difference is a property of the nucleus itself and does not depend on the chemical state of the atom.