Question

In a multi-electron atom, which of the following orbitals • described by the three quantum numbers will have the same energy in the absence of magnetic and electric fields ?
(A) $n=1,l=0,m=0$
(B) $n=2,l=0,m=0$
(C) $n=2,l=1,m=1$
(D) $n=3,l=2,m=1$
(E) $n=3,l=2,m=0$

• A. (D) and (E)
• B. (C) and (D)
• C. (B) and (C)
• D. (A) and (B)

Answer 1

Answer: (A)

(A) 1s (B) 2s
(C) 2p (D) 3d
(E) 3d
In the absence of any field, 3 d in (D) and (E) will be of equal energy.