Electron configuration of ions - 3 | Periodic Trends of the Elements

General Chemistry 1 - Electron configuration of ions - 3

Lead (Z = 77) can form 2 different cations

  1. Write the electronic configuration of Pb.
  2. From this electronic configuration, determine the two possible ions of Pb and their electronic configuration.
  1. Ground state configuration of neutral atom: 4s < 3d < 4 p < 5s < 4d < 5p< 6s < 4f < 5d
    Pb: Z = 77 ⇒ 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d7
     
  2. Ground state configuration of transition metal ions: 3d < 4s < 4p < 4d < 4f < 5s < 5p < 5d < 6s
    First, we remove electrons from the orbital 6s ⇒ 2 electrons ⇒ Pb2+
    Pb2+: 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 4f14 5d7

    Then, we remove electrons from the orbital 5d to have a half-filled orbital (half-filled orbital is stable) ⇒ 2 electrons (+ 2 from 6s) ⇒ Pb4+
    Pb4+: 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 4f14 5d5