Among the following statements, choose the correct statements.
A. In ionic solids, ions are the constituent particles.
B. Ionic solids are soft.
C. Ionic solids are electrical insulators in the solid state.
D. Ionic solids conduct electricity in molten state.
E. Ionic solids have low melting and boiling point.
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → A, C, and D only
In ionic solids the constituent particles are positive and negative ions held together by strong coulombic (electrostatic) forces. Whether an ionic solid conducts depends on whether its ions are free to move.
(A) In ionic solids, ions are the constituent particles — True. Example: \( \ce{Na^{+}} \) and \( \ce{Cl^{-}} \) in NaCl.
(B) Ionic solids are soft — False. The strong coulombic forces make them hard and brittle; softness belongs to molecular solids held by weak forces.
(C) Ionic solids are electrical insulators in the solid state — True. The ions are fixed in their lattice positions and cannot carry current.
(D) Ionic solids conduct electricity in the molten state — True. On melting the ions become free to move.
(E) Ionic solids have low melting and boiling points — False. A great deal of energy is needed to overcome the strong attraction between the ions, so their melting and boiling points are high.
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):
Ionic Solids
