Find the difference between the summed free nucleon masses and the actual nuclear mass; the difference corresponds to binding energy. For mass-energy relation learning.
核子质量之和与原子核质量之差。
| Item | Formula / Note | Source / Standard |
|---|---|---|
| Mass defect | Δm = Σ(constituents) − bound mass | Nuclear physics |
| Binding energy | B = Δm c² | Einstein 1905 |
| Conversion | 1 u = 931.494 MeV/c² | CODATA 2018 |
| Atomic mass unit | 1 u = 1.66054×10⁻²⁷ kg | SI definition |
| Electron bookkeeping | Atomic masses cancel electrons | Calculation convention |
| Data source | Atomic Mass Evaluation 2020 | AME2020 |
Constants used on this page and their authoritative sources, for verification and citation
| Constant | Value | Unit | Source |
|---|---|---|---|
| Atomic mass constant (1 u) | 1.66053906660e-27 | kg | CODATA 2018 (1/12 of m(12C)) |
| Speed of light in vacuum c | 299 792 458 | m·s⁻¹ | SI defining constant (exact) |
| Elementary charge e | 1.602176634e-19 | C | SI defining constant (exact) |
| Avogadro constant N_A | 6.02214076e23 | mol⁻¹ | SI defining constant (exact) |
Note: 1 u·c² = 931.49410242 MeV (CODATA 2018); this factor is used directly when converting mass defect to energy.
工作与生活中的相关计算与查询。