PhysicsChapter 8: Nuclear Physics
Nuclear Reactions and Q-Value
A nuclear reaction
Definition
A nuclear reaction is a process in which nuclei or nuclear particles interact and produce different nuclei or particles. The Q-value represents the net energy released or absorbed in a nuclear reaction.
Q-Value
A general nuclear reaction can be represented as: a + X → Y + b Conservation laws must be satisfied, including: electric charge; total energy; momentum; nucleon/baryon number in ordinary nuclear reactions. The energy difference between initial and final rest masses is: **Q=(minitial−mfinal)c² If: Q>0 energy is released. If: Q<0 energy must be supplied. When masses are in atomic mass units: Q(MeV)=Δm(u)×931.5**
Formula / Key Relation
**Q=(mi−mf)c²**
Exam preparation
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Review the key facts, formulas and checks before you move on.Nuclear Reactions and Q-Value
Sticky Notes · Quick Revision
`Q=(mi−mf)c²`
- Q positive → released
- Q negative → required
60-second revision
- Q-value connects nuclear mass differences to reaction energy.
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