electron config in the "d" sublevel

[Haowen_Liang_3E]

For the electron configuration, when we get into an element in the "d" sublevel, why do we do something like "3d¹⁰ 4s¹" instead of "3d⁹ 4s²?"

[Adam Yaptangco 1D]

I believe that the d subshell must be completely filled first before it can move onto the next one.

[JulietOttenberg-1C]

Excluding exceptions, the sublevels are filled from lowest to highest energy. The 3d sublevel gets filled before any of the sublevels after it (such as 4p and 5s and 4d) because it has a lower energy

[204750609]

I think you fill in the 4s level before the 3d level because the 3d level has a slightly higher energy than the 4s sub level.
https://www.chemguide.co.uk/atoms/prope ... oblem.html

[105012653 1F]

If we're finding the electron configuration for, say, an ion with the same amount of electrons, would it also follow the same rule?

[Chem_Mod]

For ions, find the electron configuration of the neutral atom first. Then add/subtract the electrons from lowest unfilled orbital/highest filled orbital.