Question

Explain in brief with one example of an ionic bond.

Answer 1

The bond formed by the complete transfer of one or more electrons from an electropositive atom to an electronegative atom, leading to the formation of ions that are held together by electrostatic attraction is called an ionic bond or electrovalent bond.

Formation of sodium chloride (NaCl):

1. The electronic configurations of sodium and chlorine are:
   Na (Z = 11): 1s² 2s² 2p⁶ 3s¹ or (2, 8, 1)
   Cl (Z = 17): 1s² 2s² 2p⁶ 3s² 3p⁵ or (2, 8, 7)
2. Sodium has one electron in its valence shell. It has a tendency to lose one electron to acquire the electronic configuration of the nearest inert gas, neon (2, 8).
3. Chlorine has seven electrons in its valence shell. It has a tendency to gain one electron and thereby acquire the electronic configuration of the nearest inert gas, argon (2, 8, 8).
4. During the combination of sodium and chlorine atoms, the sodium atom transfers its valence electron to the chlorine atom.
5. Sodium atom changes into Na+ ion while the chlorine atom changes into Cl ion. The two ions are held together by strong electrostatic force of attraction.
6. The formation of ionic bond between Na and Cl can be shown as follows:
   
   \[\ce{Na^+ + Cl^-->\underset{\text{Ionic bond}}{Na^+Cl^-}}\] or NaCl