Orbital Energy Levels

[304655635]

Is the 4s orbital's energy higher than that of the 3D orbital?

[Abigail Yap 2K]

Hello! Yes, the 4s orbital has a higher energy than the 3d orbital.

[Christine Wastila 1H]

The 4s orbital is lower energy than the 3d orbital for Ca and K because they do not have electrons in the 3d state. However, after the 4s orbital is occupied and electrons enter the 3d state, 3d is then lower energy than 4s. For example, the electron configuration for Scandium is Sc: [Ar] 3d1 4s2.

[Zane Mills 1E]

^ this is exactly correct. It is important to note when writing the different energy occupied orbitals that the HIGHER energy orbitals are written last, thus the most vulnerable to lose a valence electron.