Question

the electrons enter into 4S orbital after filling 3p orbital but not into 3D explain the reason it is for 2 marks​

Answer 1

Answer:

Because 4S sub electronic shell comes before 3D

according to AufBau principle

FOLLOW

Answer 2

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As per Aufbau principle, electron enters into the orbital whose (n + l) value is less. The (n + l) values for 4a and 3d are

4s = 4 + 0 = 4

3d = 3 + 2 = 5

Here the (n + l) value of 4s < 3d. Hence electron enters into 4s orbital after filling '3p' instead of '3d'