The description of the positions of the electrons around a nucleus is called an electron configuration. We can determine the shape and energy of an atomic species' electrons by looking at its electron configuration, whether it is neutral or ionic. That is why it is important to find and write electron configuration of chemical elements. If you are wondering how to find electron configuration, this write-up will assist you with that along with examples and uses.

how to find electron configuration?

Method 1: Using the Periodic Table

The periodic table is the most useful resource for figuring out electron configurations. The number of protons and electrons in a neutral atom, which is the atomic number, is used to identify each element. For instance, the atomic number 6 of carbon (C) indicates that it has six electrons.

Find, find where the carbon belongs which is in the second period (row) and second group (column) of the periodic table.
In the next step,start with the lowest energy level (n=1) and fill the orbitals that are open.
A maximum of two electrons (1s2) can be accommodated in the first energy level.
Once all six electrons have been assigned, proceed to the second energy level (n=2) and fill the 2s and 2p subshells.

Method 2: Pauli Exclusion Principle

So, how to find electron configuration? This fundamental criterion for electron configuration is known as the Pauli exclusion principle. The greatest number of electrons that can fit into each orbital is two, and they must have opposing spins.

Let's examine the electron configuration of nitrogen (N), which has an atomic number of seven.

The electron configuration is 1s2 2s2 when the first two subshells are filled. Up to six electrons can fit inside the 2p subshell in the 2px, 2py, and 2pz orbitals.
We add one electron to each orbital since the Pauli exclusion principle requires that the electrons in the 2p subshell have opposing spins.
This results in: s2, s2, px1, py1, and pz1.

Method 3: Aufbau Principle

An important formula in electron configuration, the Aufbau principle, is based on the notion that electrons first fill lower-energy orbitals before moving to higher-energy ones. You start at the lowest energy level (n=1) and work your way up to higher energy levels, as we saw with the periodic table method.

In order to understand how to find electron configuration using Aufbau principle, let’s find out the electron configuration of silicon (Si) as an example, which has an atomic number of 14.

We need to fill the 1s, 2s, and 2p subshells.
Stop when all 14 electrons have been utilised.
The resulting electron configuration is 1s2 2s2 2p6 3s2 3p2.

Method 4: Hund's Rule

According to this concept, electrons can only occupy degenerate orbitals that have the same energy level as them. This rule states that electrons prefer to occupy multiple parallel spin orbitals rather than teaming up in the same orbital unless necessary.

To understand Hund's rule, let's take nitrogen (N) as an example.

The electron configuration to be 1s2 2s2 2px1 2py1 2pz1.
Before any of the three 2p orbitals begin partnering up, we can observe that they are all equipped with a single electron.

Method 5: Noble Gas Configuration Shortcut

If you want to know how to find electron configuration in a shortcut method, the noble gas configuration method is the solution. Writing down the complete electron configuration for bigger elements can be time-consuming. However, we may speed up the procedure by using a shortcut based on the configuration of noble gases as they are very stable.

Let’s find the electron configuration of selenium (Se) as an example which has an atomic number of 34.

Argon (Ar), which has the nearest lower atomic number and an electron configuration of [Ne] 3s2 3p6, is a noble gas.
The remaining selenium electrons are simply added after argon's configuration to create the selenium electron configuration.
The configuration is [Ar] 3d10 4s2 4p4.

Method 6: Electron Configuration Charts or Tables

On many occasions, you may come across components whose electron configurations are intricate and difficult to ascertain manually. Charts or tables of electron configurations are useful tools for quickly and precisely determining electron configurations.

These graphs provide systematic lists of the electron configurations for every element. Directly from the chart or table, you can find the element's atomic number and read its associated electron configuration. You can find the chart and table in any chemistry book.

Uses of electron configuration

Now that you know how to find electron configuration, let’s have a look at the uses of it.

1.Chemical bonding and reactivity

Understanding electron configuration is essential to comprehending chemical bonding and reactivity. Elements tend to add, lose, or share electrons to obtain a stable configuration. It is generally done by achieving a noble gas configuration.

2.Magnetism and Magnetic Properties

Magnetic behaviour can be caused by unpaired electrons in an atom's electron configuration. Materials with unpaired electrons are magnetic because they are drawn to a magnetic field. It is crucial to comprehend a compound's electron configurations to predict their magnetic properties.

3.Periodic trends and Chemical behaviour

It is really important to know how to find electron configuration because it has a direct impact on both an element's position in the periodic table and its chemical characteristics or behaviour. The outer electron configurations of elements in the same group or column of the periodic table are comparable.

4.Transition Metals and Complex Ions

Because transition metals have partially filled d orbitals, their electron configurations can be more complicated. These partially filled orbitals are important in the chemistry of transition metals. Transition metal complexes are often utilised in industrial processes and medical treatments.

5.Atomic structure and spectroscopy

Spectroscopic methods, such as atomic emission and absorption spectroscopy, rely on the transitions in electron energy levels within atoms. The energy levels and transitions are determined by the electron configuration, allowing us to identify elements and to examine their atomic structure.