How to write electron config for Bi3+?

[Melody Zhang 3L]

For the hw problem, 3.5 part b, the ground state electron configuration for Bi3+ was 4f14, 5d10, 6s2. I thought it would be just 6s2 because the electron configuration of Bi is 6s2, 6p3. Can someone clarify where the 4f14 and 5d10 came from?

[Tam To 1B]

Xenon's electron configuration is [Kr]4d^10, 5s^2, 5p^6. The ground state electron configuration for Bi is [Xe]4f^14, 5d^10, 6s^2, 6p^3 because you have to continue off that sequence. The 4f^14 and 5d^10 are from period 6 Lanthanoids and transition metals. It may not show as a single row on the PT, but remember that the lanthanoids go in period 6 as well.