Q. When hydrogen atom is in its first excited level, its radius is …… its ground state radius
A) Half
B) Same
C) Twice
D) Four times
Explanation
(d) $r \propto n^{2}$. For ground state $n = 1$ and for first excited state $n = 2$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.