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NEETChemistryd and f Block Elements

While filling up of electrons in the atomic orbitals, the 4s orbital is filled before the 3d orbital but reverse happens during the ionization of the atom. Explain why?

Options

  1. AElectrons follow the Aufbau principle while filling orbitals.
  2. BThe 4s orbital has a higher energy level than the 3d orbital.
  3. CThe 3d orbital has a lower energy level than the 4s orbital.
  4. DElectrons preferentially occupy orbitals with higher principal quantum numbers.

Correct answer

C. The 3d orbital has a lower energy level than the 4s orbital.

Step-by-step solution

Correct Option is : (C) The 3d orbital has a lower energy level than the 4s orbital.

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