Q. Correct energy value order is
A) $ns,\ np,\ nd,\ (n - 1)f$
B) $ns,\ np,\ (n - 1)d,(n - 2)f$
C) $ns,np,\ (n - 1)d,\ (n - 1)f$
D) $ns,(n - 1)d,np,(n - 1)f$
Explanation
(d)
Subshell having lower value of $(n + l)$ will be of lower energy, where $n$ is the principle and $l$ is the azimuthal quantum number. Thus,
Correct energy value order is
$ns,(n - 1)d,\ np,(n - 1)f$.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.