Question

Which of the two orbital is filled first and why? 2s or 3f​

Answer 1

Answer:

The oddity is the position of the 3d orbitals, which are shown at a slightly higher level than the 4s. This means that the 4s orbital which will fill first, followed by all the 3d orbitals and then the 4p orbitals. Similar confusion occurs at higher levels, with so much overlap between the energy levels that the 4f orbitals do not fill until after the 6s, for example.

Answer 2

Answer:

hope it is helpful to you.