The composition of an $\alpha $- particle can be expressed as
$1P + 1N$
$1P + 2N$
$2P + 1N$
$2P + 2N$
Pauli suggested the emission of nutrino during $\beta^{+}$decay to explain
The radioactive nucleus $_7{N^{13}}$decays to $_6{C^{13}}$ through the emission of
An element $A$ decays into element $C$ by a two step process :
$A \to B + {\;_2}H{e^4}$
$B \to C + \;2{e^ - }$
Then
Suppose a ${ }_{88}^{226} Ra$ nucleus at rest and in ground state undergoes $\alpha$-decay to a ${ }_{56}^{22} Rn$ nucleus in its excited state. The kinetic energy of the emitted $\alpha$ particle is found to be $4.44 MeV$. ${ }_{86}^{22} Rn$ nucleus then goes to its ground state by $\gamma$-decay. The energy of the emitted $\gamma$-photon is. . . . . . . .$keV$,
[Given: atomic mass of ${ }_{ gs }^{226} Ra =226.005 u$, atomic mass of ${ }_{56}^{22} Rn =222.000 u$, atomic mass of $\alpha$ particle $=4.000 u , 1 u =931 MeV / c ^2, c$ is speed of the light $]$
A nucleus decays by ${\beta ^ + }$ emission followed by a gamma emission. If the atomic and mass numbers of the parent nucleus are $Z$ and $A$ respectively, the corresponding numbers for the daughter nucleus are respectively.