Question

Which of the following arrangement is possible?

	n	l	m	s
a	5	2	2	$+ 1/2$
b	2	2	0	$-1/2$
c	3	-2	1	$+1/2$
d	0	0	1	$+1/2$

• A. a
• B. b
• C. c
• D. d

Answer 1

Answer: (A)

For a given value of $n, l = 0$ to $n - 1$;

for a given value of $l, m = -l$ to $+l$ including zero;

for a given value of $m, s =+\frac{1}{2},-\frac{1}{2}$

∴ When $n = 5$, then $l = 0, 1, 2, 3, 4$;

when $l = 2$, then $m = -2, -1, 0, +1, +2$

The value of s can be $±1/2$

Hence, the arrangement, $n = 5, l = 2, m = 2, s = +1/2$

is possible for an electron.