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प्रश्न
The mass of a H-atom is less than the sum of the masses of a proton and electron. Why is this?
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उत्तर
Einstein’s mass-energy equivalence gives E = mc2. Thus the mass of an H-atom is `m_p + m_e - B/c^2` where B ≈ 13.6 eV is the binding energy.
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