Q. Which of the following molecules has three fold axis of symmetry?
A) $NH_{3}$
B) $C_{2}H_{4}$
C) $CO_{2}$
D) $SO_{2}$
Explanation
(a)
A molecule is said to possess a three-fold axis of symmetry if on rotation around this axis through an angle of 360/3, $ie,$ 120${^\circ}$,gives the same arrangement of atoms. Since $NH_{3}$ has a pyramidal geometry, therefore, it has a three fold axis of symmetry
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.