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NEETChemistryd and f Block Elements

Why does Cr have the electronic configuration 3d54s1 instead of 3d44s2?

Options

  1. ABecause 3d orbitals are completely filled
  2. BBecause of the energy gap between 3d and 4s orbitals
  3. CBecause 4s orbitals are completely filled
  4. DBecause of the little energy difference between (n-1)d and ns orbitals

Correct answer

B. Because of the energy gap between 3d and 4s orbitals

Step-by-step solution

The energy gap between the 3d and 4s orbitals is small enough to prevent electrons from entering the 3d orbitals.

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