Question

A solid is hard and brittle. It is an insulator in solid state but conducts electricity in molten state. The solid is a

• A. molecular solid
• B. ionic solid
• C. metallic solid
• D. covalent solid

Answer 1

The correct option is B ionic solid

Ionic solid is hard and brittle like $NaCl$.
It is an insulator in solid state but in molten state it conducts electricity as it has free ions in molten state.