Chemical formula of laughing gas is:

The correct answer is Option (2) → \(N_2O\)

Dinitrogen oxide, N₂O, is the oxide of nitrogen called laughing gas.

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):
Oxides of Nitrogen – …