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

The correct option is A (D) and (E)

The energy of an orbital is given by $(n+l)$ value.
Here,
(A) $n+l=1+0=1$
(B) $n+l=2+0=2$
(C) $n+l=2+1=3$
(D) $n+l=2+3=5$
(E) $n+l=2+3=5$

So, (D) and (E) will have same energy