order

[connie 2C]

how come in some electron configurations the d-orbital comes before the s-orbital like in titanium?

[Montana James 4G]

I think it's because the d-orbital has lower energy than the s-orbital for some elements

[Ryan Chang 1C]

D-orbitals have a slightly lower energy level than s-orbitals in the same period, therefore d-orbitals are filled with electrons first before s-orbitals. For example, the 3d orbital would be filled with electrons before the 4s orbital.

[Jared Khoo 1G]

With some exceptions where the s orbital is lower energy, since the d orbital is in a different shell you order that first. Eg. 4d then 5s.