Question

Find the minimum and maximum value of (n+l+m) in first excited state of unpaired electron (last) of Cl.

Answer 1

The electronic configuration of chlorine ground state is
1s²2s²2p⁶3s²3p⁵
The electronic configuration of chlorine first excited state is
1s²2s²2p⁶3s²3p⁴4s¹
So, this electron is on 4s orbital and can be characterized by the following quantum numbers:
n = 4
l = 0
m = 0
The minimum and maximum value of (n+l+m) coinciding and equals to 4
Answer: 4