Which of the following are not characteristic properties of ionic solids?
A. The bonding forces are Coulombic or electrostatic attraction.
B. They are hard but brittle.
C. They are malleable and ductile.
D. They are insulators in solid and liquid states.
E. Their melting points are high.
Choose their correct answer from the options given below.
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → C and D only
Ionic solids are made of positive and negative ions held by strong electrostatic (Coulombic) forces. They are hard but brittle and have high melting points. Their ions are fixed in the solid, so they are insulators in the solid state but conduct in the molten state, where the ions can move.
A. The bonding forces are Coulombic or electrostatic attraction. — A characteristic property of ionic solids. The ions are held by electrostatic attraction.
B. They are hard but brittle. — A characteristic property of ionic solids. A small shift brings ions of like charge next to each other, so the crystal breaks.
C. They are malleable and ductile. — Not a characteristic property of ionic solids. Malleability and ductility are properties of metallic solids.
D. They are insulators in solid and liquid states. — Not a characteristic property of ionic solids. They are insulators only in the solid state; molten ionic solids conduct.
E. Their melting points are high. — A characteristic property of ionic solids. Much energy is needed to overcome the strong attraction between the 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):
Classification of Crystalline Solids – …
