Question

Which of the following pairs is isoelectronic?

• A. $Ar$ and $Cl$
• B. $N{a}^{+}$ and $Ne$
• C. $N{a}^{+}$ and $Mg$
• D. $Mg$ and $Ne$

Answer 1

Answer: (B)

Ar contains 18 electrons.
Cl contains 17 electrons.
Na${}^{+}$ contains 10 electrons.
Ne contains 10 electrons.
Mg contains 12 electrons