Chemistry - GENERAL CHEMISTRY Question with Solution | TestHub

Order of electron filling is

1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶.......

It should be 1s²2s²2p¹
In this case$2\text{p}$started filling before 2s, violating aufbau’s principle.
In$2{\text{p}}_{\text{x}}$two electrons have parallel spin. This violates pauli’s exclusion principle.