Aufbau principle does not give the correct arrangement of filling Up of atomic orbitals in

Question

Aufbau principle does not give the correct arrangement of filling Up of atomic orbitals in (A) Cu and Zn (B) Co and Zn (C) Mn and Cr (D) Cu and Cr

Tardigrade Admin · Accepted Answer

Aufbau principle does not give the correct arrangement of filling up of atomic orbitals in copper and chromium because half-filled and completely filled electronic configuration of

C r

and

C u

have lower energy and therefore, more stable.

C r (Z = 24) : 1 s^{2}, 2 s^{2} 2 p^{6}, 3 s^{2} 3 p^{6} 3 d^{5}, 4 s^{1}

C u (Z = 29) : 1 s^{2}, 2 s^{2} 2 p^{6}, 3 s^{2} 3 p^{6} 3 d^{10}, 4 s^{1}

Q. Aufbau principle does not give the correct arrangement of filling Up of atomic orbitals in

Cu and Zn

Co and Zn

Mn and Cr

Cu and Cr