Atomic Structure Result Question 15-1

15. The correct set of four quantum numbers for the valence electrons of rubidium atom $(Z=37)$ is

(2013 Main)

(a) $5,0,0,+\dfrac{1}{2}$

(b) $5,1,0,+\dfrac{1}{2}$

(c) $5,1,1,+\dfrac{1}{2}$

(d) $5,0,1,+\dfrac{1}{2}$

Show Answer

Answer:

Correct Answer: 15. ( a )

Solution:

  1. Given, atomic number of $\mathrm{Rb}, Z=37$

Thus, its electronic configuration is $[\mathrm{Kr}] 5 s^1$. Since, the last electron or valence electron enter in $5 s$ subshell.

So, the quantum numbers are $n=5, l=0$, (for $s$-orbital) $m=0$

$(\because m=+l$ to $-l), s=+1 / 2$ or $-1 / 2$.