Which of the following pairs are isoelectronic with one another?

Consider an imaginary ion ${}_{22}^{48}X^{3-}$. The nucleus contains '$a$'$\%$ more neutrons than the number of electrons in the ion. The value of '$a$' is $.....$ [nearest integer].

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

An element has an atomic mass of $19$ and an atomic number of $9$. How can its ion be represented?

What are the similarities and differences between $Mg$ and $Mg^{2+}$?

Calculate the number of electrons,protons,and neutrons in $Cl_{2}$,$Cl$,and $Cl^{-}$. (Given for $Cl$: $Z = 17$ and $A = 35$)