Electron configuration of ions - 3 | Electron Configurations and Periodic Trends

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 ⇒ 1s2s2p3s3p4s3d10 4p5s4d10 5p6s4f14 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+: 1s2s2p3s3p4s3d10 4p5s4d10 5p4f14 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+: 1s2s2p3s3p4s3d10 4p5s4d10 5p4f14 5d5