β⁻ decay: a neutron in nucleus converts to:
AJust an electron
BProton + electron + antineutrino
CTwo neutrons
DPhoton
Answer & Solution
Correct answer: B. Proton + electron + antineutrino
β⁻: n → p + e⁻ + ν̄_e. Z increases by 1, A unchanged. Weak interaction. Antineutrino emitted (conservation of lepton number). β⁻ decay common for neutron-rich nuclei.
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