JEE MAIN - Chemistry (2002 - No. 41)
$$\beta$$ - particle is emitted in radioactivity by
conversion of proton to neutron
from outermost orbit
conversion of neutron to proton
$$\beta$$ -particle is not emitted
Paliwanag
$${}_0{n^1} \to {}_{ + 1}{p^1} + {}_{ - 1}{e^{}}$$