Physics · Composition and size of nucleus, atomic masses, mass-energy relation, mass defect

A nucleus with atomic number and neutron number N undergoes two decay processes.

A nucleus with atomic number \( z \) and neutron number N undergoes two decay processes. The result is a nucleus with atomic number Z-3 and neutron number N-1. Which decay processes took place?

  • A. Two \( \beta^{-} \) decays
  • B. Two \( \beta^{+} \) decays
  • C. \( A n \alpha-d e c a y \) and \( a \beta^{-} \) decay
  • D. An \( \alpha- \) decay and a \( \beta^{+} \) decay

Step-by-step solution

An α-decay reduces atomic number by 2 and neutron number by 2. A β+ decay reduces atomic number by 1 and increases neutron number by 1. Combining these: ΔZ = -2 -1 = -3, ΔN = -2 +1 = -1, matching the given changes. Thus, the processes are one α-decay and one β+ decay.
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