Question

Which of the following compound are formed by ionic bonding?

• A. $\text{KCl}$
• B. ${\text{CO}}_2$
• C. $\text{MgO}$
• D. ${\text{Cl}}_2$

Answer 1

Answer: (A), (C)

The correct options are
A $\text{KCl}$
C $\text{MgO}$

Ionic bond is formed by the transfer of electrons between the atoms.

$\bullet$ Potassium chloride (KCl) is formed from the atoms of the constituent elements potassium and chlorine. The electronic configuration of potassium is 2, 8, 8, 1 and chlorine is 2, 8, 7. In order to gain stability, the potassium atom loses one valence electron and transfers it to the chlorine atom.

$\bullet$ Magnesium oxide (MgO) is formed from the atoms of the constituent elements magnesium and oxygen. The electronic configuration of magnesium is 2, 8, 2 and oxygen is 2, 8, 6. In order to gain stability, the magnesium atom loses its two valence electrons and transfers it to the oxygen atom.