When a nucleus emits a beta minus particle, its atomic number
Correct answer: B. increases by 1, while the mass number is unchanged
- A. decreases by 1
- B. increases by 1, while the mass number is unchanged
- C. decreases by 2
- D. is unchanged
Explanation
A neutron converts into a proton, an electron and an antineutrino, so the nucleus gains a proton while the total nucleon count stays the same, moving the element one place forward in the periodic table. The emitted electron comes from the nucleus, not from the electron shells. Gamma emission, by contrast, changes neither number.
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About Radioactive Decay
Radioactive decay is the spontaneous transformation of unstable nuclei, described by decay constant, activity, half life and the exponential decay law. Work includes alpha, beta and gamma emissions, decay equations and remaining nuclei, with half life distinguished from the time required for complete decay.
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