Explain the basic nuclear process by equation in $\beta$-decay.

(N/A) Although the nucleus does not contain electrons,positrons,or neutrinos,it can emit these particles during radioactive decay.
In an unstable nucleus that contains an excess neutron,the neutron is converted into a proton to achieve stability. This process is represented by the equation:
$n \rightarrow p + e^{-} + \bar{\nu}$
This is called $\beta^{-}$-decay.
In an unstable nucleus that contains an excess proton,the proton is converted into a neutron to achieve stability. This process is represented by the equation:
$p \rightarrow n + e^{+} + \nu$
This is called $\beta^{+}$-decay.
Note that while a free neutron decays into a proton,the decay of a proton into a neutron is only possible inside the nucleus. Since a free proton has a smaller mass than a neutron,the decay of a free proton is not energetically possible.