Electron Configuration for silver [ENDORSED]

[Eryn Wilkinson 3H]

In lecture we went over how the 4s orbital gets filled before the 3d orbital because it has a lower energy. Is this the same for all levels? I thought that it was, but the electron configuration given for silver in the solutions manual (ch. 2 #43) is [Kr]4d^105s^1. Can someone please explain this to me? Thank you!

[Curtis Wong 2D]

So I believe that since 3d has a lower energy level than 4s, we fill up the 3d orbital before the 4s orbital. Thus for Silver, we start to fill up the 5s orbital. However, on page 47 in the textbook, it states that the "half-complete subshell configuration d⁵ and complete subshell configuration d¹⁰ turn out to have lower energy than simple theory suggests," so it messes up electron configuration I believe.