Question

Correct set of four quantum numbers for the valence (outermost) electrons of rubidium (Z = 37) is:

(a) 5, 0, 0, + 1/2

(b) 5, 1, 0, + 2

(c) 5, 1, 1, + 1/2

(d) 6, 0, 0, + 1/2

Answer 1

Correct option is (a) 5, 0, 0, + 1/2

Electronic configuration of Rb (37) is: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 5s¹.

So for the valence shell electron (5s¹): n = 5, 1 = 0, m = 0, s = \(\frac 12\)