Question

The number of planes of symmetry in this compound is :

• A. 1
• B. 2
• C. 3
• D. 4

Answer 1

Answer: (C)

3

Answer 2

For the given structure (naphthalene), the molecule is planar and belongs to the D₂h point group. In D₂h, there are three mirror (symmetry) planes:

• The plane of the molecule (σₕ).
• Two perpendicular vertical planes (σᵥ) – one along the long axis and one perpendicular to it.

Thus, the number of planes of symmetry is 3.