When atomic masses are used to calculate the binding energy of a neutral atom, which expression is most convenient? Here mₕ is the mass of a neutral hydrogen atom.
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Question

When atomic masses are used to calculate the binding energy of a neutral atom, which expression is most convenient? Here mₕ is the mass of a neutral hydrogen atom.

G1 Physics · Accepted Answer

If atomic masses are used, it is convenient to use the neutral hydrogen-atom mass mₕ instead of the proton mass mₚ. A neutral atom contains Z electrons. The Z electron masses included in Zmₕ are then automatically balanced by the Z electron masses already present in M(atom). Hence, Δm = Zmₕ + Nmₙ − M(atom). This avoids separately subtracting electron masses. Correct option: B.