Question

Two electrons in $K$-shell will differ in:

• A. principal quantum number.
• B. spin quantum number.
• C. azimuthal quantum number.
• D. magnetic quantum number.

Answer 1

Answer: (B)

spin quantum number.

Two electrons in K-shell will differ in spin quantum number.
They will have same values for the principal quantum number, azimuthal quantum number, and magnetic quantum number.
For first electron, $n=1,l=0,m=0,s=\frac{+1}{2}$
For second electron, $n=1,l=0,m=0,s=\frac{-1}{2}$