Question

For the configuration $1s^{2}2s^1$, the quantum numbers for the outermost electron are:

• A. $2,0,0,-1/2$
• B. $2,0,0,+1/2$
• C. $2,1,0,+1/2$
• D. $2,0,1,+1/2$

Answer 1

The correct option is B $2,0,0,+1/2$

Electronic configuration	$n$	$l$	$m$	$s$
$1s^{2}2s^1$	2	0	0	$+\frac{1}{2}$