Correct order of intermolecular forces of attraction in the following solids is:
A. \(NaCl\)
B. \(I_2\)
C. \(Ice\)
D. \(Iron\)
E. \(Rubber\)
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → E, B, C, D, A
The solids are arranged by the attractive forces that hold their particles together, from the weakest to the strongest:
E. Rubber (first, weakest) — an elastomer; its polymer chains are held by the weakest intermolecular forces, which is why it can be stretched.
B. I2 (second) — a non-polar molecular solid; its molecules are held by weak dispersion (London) forces.
C. Ice (third) — a hydrogen-bonded molecular solid; hydrogen bonds are stronger than dispersion forces.
D. Iron (fourth) — a metallic solid; positive ions are held in a sea of delocalised electrons by metallic bonding.
A. NaCl (last, strongest) — an ionic solid; strong Coulombic attraction between \( \ce{Na+} \) and \( \ce{Cl-} \) ions.
Note: This question is from the pre-rationalised NCERT book (2022-23). The topic is not there in the latest NCERT book (2026-27), and it is also out of the CUET 2026 syllabus.
NCERT (Pre-rationalised edition, 2022-23):
Different Types of Solids (rows of Table 1.2)
| Type of Solid | Constituent Particles | Bonding/Attractive Forces | Examples |
|---|---|---|---|
| (1) Molecular solids (i) Non polar | Molecules | Dispersion or London forces | Ar, CCl4, H2, I2, CO2 |
| (iii) Hydrogen bonded | Molecules | Hydrogen bonding | H2O (ice) |
| (2) Ionic solids | Ions | Coulombic or electrostatic | NaCl, MgO, ZnS, CaF2 |
| (3) Metallic solids | Positive ions in a sea of delocalised electrons | Metallic bonding | Fe, Cu, Ag, Mg |
Elastomers – “These are rubber – like solids with elastic properties. In these elastomeric polymers, the polymer chains are held together by the weakest intermolecular forces.”