Question

A plot of the number of neutrons $\left(N\right)$ against the number of protons $\left(P\right)$ of stable nuclei exhibits upward deviation from linearity for atomic number, $Z>20$. For an unstable nucleus having $N/P$ ratio less than $1$, the possible mode(s) of decay is(are):

• A. ${\beta }^{-}$ - decay ($\beta$ emission)
• B. orbital or K - electron capture
• C. neutron emission
• D. ${\beta }^{+}$ - decay (positron emission)

Answer 1

Answer: (B), (D)

The correct options are
B orbital or K - electron capture
D ${\beta }^{+}$ - decay (positron emission)

$\frac{n}{P}$ ratio should increase and for that number of neutron should increase and proton should decrease.

${}_0{e}^{-1}{+}_1{P}^1{\to }_1{n}^0$ (K-electron capture)

${}_1{P}^1{\to }_1{n}^0{+}_{+1}{\beta }^0$ (${\beta }^{+}$ decay)

In both cases the number of neutron increase by 1 and proton decrease by 1.