Question

An ionic compound AB is most likely to be formed when:

• A. The ionisation energy of A is high and electron affinity of B is low
• B. The ionisation energy of A is low and electron affinity of B is high
• C. Both, the ionisation energy of A and electron affinity of B are high
• D. Both, the ionisation energy of A and electron affinity of B are low

Answer 1

The correct option is B The ionisation energy of A is low and electron affinity of B is high

The formation of an ionic compound depends on:
$1.$ Ionization energy
$2.$ Electron affinity

Ionization energy is the energy required to remove an electron from an isolated gaseous atom from its outermost valence shell. Lower the ionization energy, greater is the ease of formation of an ionic bond.

Electron affinity is the energy released when an electron is added to an isolated gaseous atom to form a negative ion. Higher the electron affinity, greater is the ease of formation of an ionic bond.