See explanation.

Noble Gas notation, also known as core notation is a shortened version of the format for electron configurations using the noble gas to represent the completed orbitals of the atoms structure.

Here are three examples using Iodine (I), Germanium (Ge) and Zirconium (Zr).

Iodine (I) would have a standard of

##1s^2 2s^2 2p^6 3s^2 3p^ 4s^2 3d^10 4p^6 5s^2 4d^10 5p^5##

The noble gas in the row above iodine is krypton

We can replace ##1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^6## with the symbol [Kr] and rewrite the noble gas configuration of iodine as

##[Kr] 5s^ 2 4d^10 5p^5##

Germanium (Ge) is located in the 4th energy level (row) of , column 14 (IVA). This position would be an electron configuration of

##1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^2##

To convert this to the Noble Gas notation we revert back to the Noble Gas from period 3 of the periodic table Argon

Argon – Ar ##” “1s^2 2s^2 2p^6 3s^2 3p^6##

We then replace this section of Germanium’s electron configuration with [Ar].

##[Ar] 4s^2 3d^10 4p^2##

Zirconium (Zr) is located in the 5th energy level (row) of the periodic table, column 4 (IVB). This position would be an electron configuration of

##1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^6 5s^2 4d^2##

To convert this to the Noble Gas notation we revert back to the Noble Gas from period 4 of the periodic table Krypton

Krypton – Kr ##” “1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^6##

We then replace this section of Zirconium’s electron configuration with [Kr].

##[Kr] 5s^2 4d^2##

I hope this was helpful.

SMARTERTEACHER