WAEC - Chemistry (2013 - No. 6)
Which of the following arrangements represents the correct order of electronic energy level?
1s 2p 2s 3p 3s 3d 4s
1s 2s 2p 3s 3p 3d 4s
1s 2s 2p 3s 3p 4s 3d
1s 2s 3s 2p 3p 4s 3d
Uitleg
the correct order of electronic energy level is OPTION C according to the Aufbau principle.