The relative strength of interionic/intermolecular forces in decreasing order is :

Solution

Chemistry ma’am · 3 steps

Ask how much charge each partner carries: two full charges beat one full charge, which beats none.

1. Full or partial charge. An ion carries a full charge, such as +1 or -1. A polar molecule carries only partial charges, δ+ and δ-, at its two ends. The more charge on each partner, the stronger the attraction between them.

   Interaction	Charges attracting	Strength
   Ion-ion	full charge with full charge	strongest
   Ion-dipole	full charge with partial charge	in between
   Dipole-dipole	partial charge with partial charge	weakest

2. How fast they fade. Distance gives the same order. Ion-ion attraction varies as 1/r, ion-dipole as 1/r² and dipole-dipole as 1/r³. So the attraction between partial charges also dies away fastest as the particles move apart.
3. So. The decreasing order is ion-ion > ion-dipole > dipole-dipole, which is option (d).

The idea to keep. Rank electrostatic forces by the charge on each partner: full with full, then full with partial, then partial with partial. More charge means a stronger pull.

Answer from the NTA final answer key. Solution by PrepWiser.