According to this principle, the arrangement of electrons in increasing order of energy level is called the Aufbau principle.

by- Indra Bhan

Image credit - Google.com

According to the Aufbau principle, the first electron enters the 1s orbital.

Image credit - Google.com

After the 1s orbital is complete, electrons enter the 2s orbital.

Image credit - Google.com

Similarly, as shown in the figure, electrons enter the 2p orbital. Similarly, electrons keep filling up gradually.

Image credit - Google.com

The area around the atomic nucleus where electrons are most likely to be found. It is called an atomic orbital.

Image credit - Google.com

What is an atomic orbital?

The electronic configuration is done according to the inert code rule.

Image credit - Google.com

Electronic Configuration –

According to the Aufbau principle, the distribution of electrons is done in the subshell.

Image credit - Google.com

In any atom, the distribution of electrons in the half-filled configuration and the fully-filled configuration is uniform.

Image credit - Google.com

For More reading Click on the Learn more

Image credit - Google.com