Question

The correct set of quantum numbers for valence electron of $Rb$ (atomic number 37) is:

• A. $5,0,0,-\frac{1}{2}$
• B. $5,1,0,\frac{1}{2}$
• C. $6,0,1,\frac{1}{2}$
• D. $5,1,1,\frac{1}{2}$

Answer 1

The correct option is A $5,0,0,-\frac{1}{2}$

Electronic configuration of $Rb=\left[Kr\right]5s^1$

$Rb$ is alkali metal with valence electron in 5s subshell. Hence, $n=5$

For s electron, $l=0$ and $m=0$.

$s$ can have value $\pm \frac{1}{2}$.

Thus, the correct set of quantum numbers for Rb (atomic number 37) is $5,0,0,-\frac{1}{2}$.