Chemistry

Worked example

What is the ground state electron configuration of the Sb⁺ cation?

For Sb, Z = 51 and therefore the neutral atom will contain 51 electrons. Because we have a cation, there will be one fewer electron, so we must accommodate 50 electrons in the orbitals of the atom. We fill the orbitals in order. Hence

1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s²4d¹⁰5p²

We can also write this in compact notation as [Kr]5s²4d¹⁰5p²