AlN is an example of

The correct answer is Option (2) → Covalent solid

In a covalent (network) solid, the atoms are joined by covalent bonds throughout the crystal, forming one giant molecule. Such solids are very hard, have very high melting points and are usually insulators. Diamond, \( \ce{SiO2} \) (quartz), SiC and AlN are examples.

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 – …