Question

The four quantum numbers of the valence electron of potassium are :

• A. $4, 1, 0$ and $ \frac{1}{2} $
• B. $4, 0,1 $ and $ \frac{1}{2} $
• C. $4, 0, 0$ and $ +\frac{1}{2} $
• D. $4, 1, 1,$ and $ \frac{1}{2} $

Answer 1

Answer: (C)

Write the electronic configuration of potassium and then find quantum numbers of valence shell electron.
$K=19=1 s^{2}, 2 s^{2}, 2 p^{6}, 3 s^{2}, 3 p^{6}, 4 s^{1}$
$\therefore $ Valence shell electron is $4 s^{1}$
$\therefore n=4 l=0 m=0 s=\frac{1}{2}$