QQuestion
A radioactive nucleus containing 128 nucleons emits a β-particle. After β-emission the number of nucleons present in the nucleus will be:
(a) 128
(b) 129
(c) 124
(d) 127
✓Answer
(a) 128
Explanation:
During β-emission, a neutron changes into a proton or a proton changes into a neutron. Therefore, the total number of nucleons remains unchanged.
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