Which is the correct order of orbital filling according to the Aufbau principle?

CHEMISTRY · Single correct · A Level · Chemistry · Atomic structure · Atomic structure

Problem

Which is the correct order of orbital filling according to the Aufbau principle? (1)

4s, 4p, 4d, 4f

(2)

4p, 4d, 5s, 4f

(3)

4s, 3d, 4p, 5s

(4)

4d, 4f, 5s, 5p