# Argon electron configuration

The argon electron configuration, denoted as [Ne] 3s2 3p6 or 1s2 2s2 2p6 3s2 3p6, showcases the precise arrangement of electrons within the atom. This configuration can be determined through various methods, including the aufbau principle, periodic table organization, Bohr model representation, or orbital diagram visualization.

Contents

## Methods

### Aufbau principle

• First, find electrons of argon atom

The atomic number of argon represents the total number of electrons of argon. Since the atomic number of argon is 18, the total electrons of argon are 18.

• Second, make a table of subshell and its maximum electrons

Calculate the maximum number of electrons each subshell can hold using the formula: 4ℓ + 2

Where, ℓ = azimuthal quantum number of the subshell

For s subshell, ℓ = 0
For p subshell, ℓ = 1
For d subshell, ℓ = 2
For f subshell, ℓ = 3

 subshell max. electrons s 2 p 6 d 10 f 14

This means that,

Each s subshell can hold maximum 2 electrons
Each p subshell can hold maximum 6 electrons
Each d subshell can hold maximum 10 electrons
Each f subshell can hold maximum 14 electrons

• Finally, use aufbau chart and start writing electron configuration

Remember that we have a total of 18 electrons.

According to the aufbau principle, 1s subshell is filled first and then 2s, 2p, 3s… and so on.

By looking at the chart, you can see that electrons are first filled in 1s subshell. Each s-subshell can hold a maximum of 2 electrons, so we will use 2 electrons for the 1s subshell.

So the electron configuration will be 1s2. Where, 1s2 indicates that the 1s subshell has 2 electrons.

Now we have used 2 electrons in the 1s subshell, so we have a total of 18 – 2 = 16 electrons left.

Looking at the chart, after 1s subshell now comes 2s subshell. Again, each s-subshell can hold a maximum of 2 electrons, so we will use 2 electrons for the 2s subshell.

So the electron configuration will be 1s2 2s2. Where, 2s2 indicates that the 2s subshell has 2 electrons.

Again, we have used 2 electrons in the 2s subshell, so we have a total of 16 – 2 = 14 electrons left.

After 2s subshell now comes 2p subshell. Each p-subshell can hold a maximum of 6 electrons, so we will use 6 electrons for the 2p subshell.

So the electron configuration will be 1s2 2s2 2p6. Where, 2p6 indicates that the 2p subshell has 6 electrons.

Here, we have used 6 electrons in the 2p subshell, so we have a total of 14 – 6 = 8 electrons left.

After 2p subshell now comes 3s subshell. Each s-subshell can hold a maximum of 2 electrons, so we will use 2 electrons for the 3s subshell.

So the electron configuration will be 1s2 2s2 2p6 3s2. Where, 3s2 indicates that the 3s subshell has 2 electrons.

Here, we have used 2 electrons in the 3s subshell, so we have a total of 8 – 2 = 6 electrons left.

After 3s subshell now comes 3p subshell. Each p-subshell can hold a maximum of 6 electrons, and we also have 6 electrons left, so we will use that 6 electrons for the 3p subshell.

So the electron configuration will be 1s2 2s2 2p6 3s2 3p6. Where, 3p6 indicates that the 3p subshell has 6 electrons.

Therefore, the final electron configuration of argon is 1s2 2s2 2p6 3s2 3p6. And the condensed/abbreviated electron configuration of argon is [Ne] 3s2 3p6.

Where, Ne is neon

### Periodic table

• First, get periodic table chart with spdf notation

The above image shows periodic table blocks.

The ‘s’ in s block represents that all s block elements have their valence electrons in s subshell. Similarly, the ‘p’ in p block represents that all p block elements have their valence electrons in p subshell. And so on for d block and f block.

• Second, mark location of argon on periodic table

Argon is the p block element located in group 18 and period 3. Hence, mark the location of argon on the periodic table as follows:

• Finally, start writing electron configuration

Remember that: each s subshell can hold maximum 2 electrons, each p subshell can hold maximum 6 electrons, each d subshell can hold maximum 10 electrons, and each f subshell can hold maximum 14 electrons.

Start writing electron configuration from the very first element (i.e., hydrogen) all the way up to argon.

So the electron configuration of argon will be 1s2 2s2 2p6 3s2 3p6.

### Bohr model

In the above image, 1 represents the 1st electron shell. Similarly, 2 represents the 2nd electron shell, and 3 represents the 3rd electron shell.

The 1st electron shell contains 1s subshell, the 2nd electron shell contains 2s and 2p subshells, and the 3rd electron shell contains 3s and 3p subshells.

We know that each s subshell can hold maximum 2 electrons, each p subshell can hold maximum 6 electrons, each d subshell can hold maximum 10 electrons, and each f subshell can hold maximum 14 electrons.

Also, we have to make sure that the electron configuration will match the order of aufbau principle (i.e., the 1s subshell is filled first and then 2s, 2p, 3s… and so on).

So the electron configuration of argon will be 1s2 2s2 2p6 3s2 3p6.

Where,

1s2 indicates that the 1s subshell has 2 electrons
2s2 indicates that the 2s subshell has 2 electrons
2p6 indicates that the 2p subshell has 6 electrons
3s2 indicates that the 3s subshell has 2 electrons
3p6 indicates that the 3p subshell has 6 electrons

### Orbital diagram

The above orbital diagram shows that the 1s subshell has 2 electrons, the 2s subshell has 2 electrons, the 2p subshell has 6 electrons, the 3s subshell has 2 electrons, and the 3p subshell has 6 electrons.

So the electron configuration of argon will be 1s2 2s2 2p6 3s2 3p6.