How to write the electronic configuration of elements?

Writing electronic configuration of elements is a skill every student must learn if they have a smooth ride in their chemistry journey.

But don’t worry, writing electronic configuration is really simple and I will teach you all you need to do.

I want to emphasize that there are two forms of electronic configuration; shell electronic configuration and electronic configuration.

The orbital configuration can be written with the knowledge of the electronic configuration however this article is all about electronic configuration.

I will try and elucidate the configuration of the first few elements in the periodic table.

The electronic configuration follows a regular pattern according to AufBau’s principle.

 Is 2s 2p 3s 3p 4s 3d ………..

Please remember that the sub-levels have different capacities of electrons. S orbitals contain 2 electrons, p orbital contains 6 electrons, d orbital contains 10 electrons while f orbital contains 14 electrons.

Electronic configuration of Hydrogen

To write the electronic configuration of hydrogen, you need to remember the atomic number of the element.

Hydrogen has atomic number 1.

Shell electronic configuration – 1

Electronic configuration – Is1

This is an s block element.

Electronic configuration of Carbon

To write the electronic configuration of Carbon, you need to remember the atomic number of the element.

Carbon has atomic number 6.

Shell electronic configuration – 2,4

Electronic configuration – Is²  2s² 2p²

This is a p block element

Electronic configuration of Neon

To write the electronic configuration of Neon, you need to remember the atomic number of the element.

Neon has the atomic number 10.

Shell electronic configuration – 2, 8

Electronic configuration – Is² 2s² 2p⁶

Electronic configuration of Sodium

To write the electronic configuration of Sodium, you need to remember the atomic number of the element.

Sodium has the atomic number 11.

Shell electronic configuration – 2,8,1

Electronic configuration – Is² 2s² 2p⁶ 3s¹

Electronic configuration of Alumnium

To write the electronic configuration of Aluminium, you need to remember the atomic number of the element.

Aluminium has atomic number 13.

Shell electronic configuration – 2, 8, 3

Electronic configuration – Is² 2s² 2p⁶ 3s² 3p¹

Electronic configuration of Silicon

To write the electronic configuration of Silicon, you need to remember the atomic number of the element.

Aluminium has atomic number 14.

Shell electronic configuration – 2, 8, 4

Electronic configuration – Is² 2s² 2p⁶ 3s² 3p²

Electronic configuration of Argon

To write the electronic configuration of Argon, you need to remember the atomic number of the element.

Argon has atomic number 18.

Shell electronic configuration – 2, 8, 8

Electronic configuration – Is² 2s² 2p⁶ 3s² 3p⁶

You will notice that the configuration of Nein and Argon are completely filled up.

Electronic configuration of Calcium

To write the electronic configuration of Calcium, you need to remember the atomic number of the element.

Calcium has atomic number (electron) of 20

Shell electronic configuration – 2, 8, 8,2

Electronic configuration – Is² 2s² 2p⁶ 3s² 3p⁶ 4s²

Electronic configuration of Scandium

To write the electronic configuration of Scandium, you need to remember the atomic number of the element.

Scandium has atomic number 21.

Electronic configuration – Is² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹

Electronic configuration of Manganesse

To write the electronic configuration of Manganese, you need to remember the atomic number of the element.

Manganese has atomic number 25.

Electronic configuration – Is² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁵

Hint

It is important to note that the electronic configuration of elements is based on the electrons and not on the atomic number of the elements.

Let me illustrate with examples; the electronic configuration of sodium atom (Na) is different from the electronic configuration sodium ion (Na⁺)

Na  has 11 electrons   1s² 2s² 2p⁶ 3s¹

Na⁺  has 10 electrons  1s² 2s² 2p⁶

This is a complete guide on how to write an electronic configuration of elements and deduce the number of orbitals.