Question

What is the name for the shortcut notation for an electron configuration based on the noble gases?

Answer 1

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

Iodine (I) would have a standard electron configuration 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 kryton

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^ 5d^10 5p^5`

Germanium (Ge) is located in the 4th energy level (row) of the periodic table, 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] 4s^2 3d^2`

I hope this was helpful.
SMARTERTEACHER