Question

Consider the following sets of quantum numbers:

$n$	$l$	$m$	$s$
(A) $3$	$0$	$0$	$+1/2$
(B) $2$	$2$	$1$	$+1/2$
(C) $4$	$3$	$-2$	$-1/2$
(D) $1$	$0$	$-1$	$-1/2$
(E) $3$	$2$	$3$	$+1/2$

Which of the following sets of quantum numbers is not possible?

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

Answer 1

The correct option is B (B), (D) and (E)

According to the Afbhau rule the value of quantum no is related to the

$n=$ principal quantum no.

Value of $l$ (Azimuthal quantum no.) $=n-1$

Value of $m$ ( magnetic quantum no. )$=-lto+l$

Value of $s$ (spin quantum no.) $=+1/2or-1/2$
From the above formulae of quantum no., we observe-

(B) $n\ne l$

(D) $-l<m<+l\Rightarrow atl=0,m=0$
(E) $m\ngtr l$
$\therefore$ B, D and E are not possible
Option B.