Textbook Problem 1E.25: Electron Configurations

[Vanessa_Ong_3F]

Give the notation for the valence-shell configuration including the outermost d-electrons) of (a) the alkali metals; (b) Group 15 elements; (c) Group 5 transition metals; (d) the “coinage” metals (Cu, Ag, Au).

I understand the electron's number in the s,p,d blocks, but I do not understand how we came up with the energy level. For example how we got the (n-1) portion in (n-1)d^10ns^1.

[Ethan Mai 1D]

If you are talking about the coinage metals, when the answer says (n-1) it always means that the energy level of the d-orbital in the condensed electron configuration will always be 1 less than that of the s- and p-orbitals. For example, Cu's electron configuration is [Ar]3d104s1, where the energy level of the d-orbital (3) is 1 less than the energy level of the s-orbital (4). For Ag, whose electron configuration is [Kr]4d105s1, the energy level of the d-orbital (4) is 1 less than the energy of the s-orbital (5).