Pearclasses's answer to emily's Junior College 1 H2 Maths question.

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Pearclasses
Pearclasses's answer
11 answers (A Helpful Person)
The energy gap between 2p and 3s is bigger than the energy gap between 3p and 3d, so I think thats the reason why electrons can continue to fill the 3d orbitals after the 3p orbitals are fully filled