Electronic Configuration

Electronic Configuration of Atoms:

A representation which characterizes each electron in an atom is referred to as the electronic configuration. Each element has different arrangement of electrons in various orbital. Keeping in view the above rules, the following convention is used to represent the electronic configuration of atoms. It consists of the following three steps.

• The main energy level (1, 2, 3,…) is written first.
• The sub-shell (s, p, d, f….) is written next.
• The number of electrons in the particular sub-shell is shown as the superscript to the sub-shell. e.g.

                              2 P ⁴

Where,

P = Sub-shell

2 = Main energy level

4 = No. of electrons

Electronic configuration of Ions:

Electronic configuration of ions can be written in a similar manner to those of neutral atoms. e.g.

Mg (Z=12) = 1s²2s²2p⁶3s²

Mg⁺² (Z=12) = 1s²2s²2p⁶

Cu⁺ (Z=29) = 1s²2s²2p⁶3s²3p⁶3d¹⁰

Cu⁺² (Z=29) = 1s²2s²2p⁶3s²3p⁶3d⁹.