Favourable factors for the formation of ionic bond:
The formation of an ionic bond is favoured by the following factors:
• Low ionisation energy of the cation-forming atom, so it can lose electrons easily.
• High electron affinity (or electronegativity) of the anion-forming atom, so it can gain electrons readily.
• Large difference in electronegativity between the two atoms.
• High lattice energy of the resulting ionic compound, which stabilises the crystal.
• High hydration energy (in aqueous medium), which helps stabilise ions in solution.
Final Answer:
Low ionisation energy, high electron affinity, large electronegativity difference, and high lattice energy favour the formation of an ionic bond.