Physics A-Level
Mass defect
What Mass defect means in Physics A-Level, as defined for AQA, OCR.
Definitions of Mass defect
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Reference: OCR
In nuclear fission and fusion, the total mass of the products is slightly less than that of the reactants, and this difference appears as energy.
The difference between the total mass of the separate nucleons and the actual nuclear mass, which appears as binding energy via ΔE = Δm c².
The total mass after the reaction is less than the total mass before, and this mass difference corresponds to energy released by ΔE = Δmc².
The difference between the mass of separate nucleons and the nuclear mass, from which binding energy arises through E = mc².
The difference between the total mass of a nucleus's separate protons and neutrons and the actual mass of the nucleus.
A difference in mass in nuclear reactions that is converted to energy using Einstein's mass–energy equivalence.
Topics that use Mass defect
- Mass and energy (A-level only) (AQA A-Level)
- Nuclear fission and fusion (OCR A-Level)
Related terms
- Binding energy
- Energy release in nuclear reactions
- Nuclear stability
- Alpha and beta decay
- Atomic mass unit
- Barium
- Binding energy per nucleon against nucleon number curve
- Binding energy per nucleon comparisons
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