Question

The electronic configuration of Cu (atomic number 29) is

Options

• 1s², 2s² 2p⁶, 3s² 3p⁶, 4s² 3d⁹ 

• 1s², 2s² 2p⁶, 3s² 3p⁶ 3d¹⁰, 4s¹

• 1s², 2s² 2p⁶, 3p² 3p⁶, 4s² 4p⁶, 5s² 5p¹ 

• 1s², 2s² 2p⁶, 3p² 3p⁶, 4s² 4p⁶ 3d³ 

Answer 1

1s², 2s² 2p⁶, 3s² 3p⁶ 3d¹⁰, 4s¹ 

Explanation:

Electronic configuration of Cu (29) is 1s², 2s²2p⁶, 3s² 3p⁶ 3d¹⁰, 4s¹ and not 1s², 2s² 2p⁶ 3s² 3p⁶ 3d⁹4s² due to extra stability of fully filled orbitals.