Question

based on aufbaurules arrange the following orbitals in the increasing order of energy.
1)4f,4d,7s,7p
2)5p,4d,4f,6s

Answer 1

Dear Student,

According to Aufbau’s principle, in the ground state of the atoms, the orbitals are filled in the order of their increasing energies. In other words, electrons first occupy the lowest energy orbital available to them and enter into higher energy orbital only when the lower energy orbitals are filled.

The order in which the energies of orbitals increase and hence the order in which the orbitals are filled is as follows:

1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p….

Hence, increasing order of energy is ​for
(i) 4d<4f<7s<7p

(ii) 4d<5p<6s<4f

Regards,