In d-block elements the irregularity in electronic configuration occurs in _____?

In d-block elements the irregularity in electronic configuration occurs in _____?

ڈی بلاک عناصر میں الیکٹرانک ترتیب میں بے ضابطگی _____ میں پائی جاتی ہے؟
Explanation

Elements like Cr (24), Cu (29), and Mo (42) show irregular configurations due to extra stability of half-filled or fully filled d-orbitals.

Examples:

  • Cr: [Ar] 3d⁵ 4s¹
  • Cu: [Ar] 3d¹⁰ 4s¹
  • Mo: [Kr] 4d⁵ 5s¹