UPSC One
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2016 · Q17

In the gamma decay of a nucleus

General KnowledgePhysics
  1. Athe mass number of the nucleus changes whereas its atomic number does not change
  2. Bthe mass number of the nucleus does not change whereas its atomic number changes
  3. Cboth the mass number and the atomic number of the nucleus changes
  4. Dneither the mass number nor the atomic number of the nucleus changes

Explanation

Gamma decay is the emission of a high-energy photon from an excited nucleus; it carries away energy but no nucleons and no charge. The proton number (atomic number) and the total nucleon number (mass number) therefore both remain unchanged.