Question

Which orbital is filled after $6\mathrm{s}$ ?

Answer 1

Aufbau principle:

• Aufbau's principle talks about how the arrangement of electrons is done in the atomic orbitals of an atom in its ground state.

• Above is the diagram through which one could understand the system of filling of electrons.
• And as we could evidently see that after $6\mathrm{s},$ the orbitals that are to be filled is $4\mathrm{f}.$