Q. For which one of the following, Bohr model is not valid ?
A) Singly ionised helium atom ($He^+$)
B) Deuteron atom
C) Singly ionised neon atom ($Ne^+$)
D) Hydrogen atom
Explanation
[Solution] Bohr's model applies only to one-electron systems; $Ne^+$ has 9 electrons. Answer (3).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.