If the electronic configuration of a metal ion $M^{2+}$ is $2, 8, 14$ and its atomic mass is $56 \, a.m.u.$,then the number of neutrons in its nucleus is .....

An atom has $26$ electrons and its atomic weight is $56$. The number of neutrons in the nucleus of the atom will be

Which of the following is correct?

In the atom $_{13}Al^{27}$,the number of protons $(a)$,electrons $(b)$,and neutrons $(c)$ are present. Determine the ratio in the order $(c : b : a)$.

In the two elements, ${ }_{Z_1} A^{M_1}$ and ${ }_{Z_2} B^{M_2}$, the following relations are true. $M_1 \neq M_2$ and $Z_1 \neq Z_2$ but $M_1-Z_1=M_2-Z_2$. These elements are ($M$ is atomic weight, $Z$ is atomic number)

Which of the following has an isotopic number (neutron number) equal to that in $_{13}^{27}Al$?