Aufbau Principle

[Sally kim 4F]

What is the Aufbau Principle and how does it relate to electron configuration?

[Joelle 3L]

The Aufbau principle means that electrons are added to orbitals as protons are added to the atom. Therefore, lower electron orbitals fill before the higher orbitals. This process can be seen as "building up" the electron shell. It outlines the rules on how electrons are organized in electron configuration.

[Sanjana K - 2F]

It's basically the "building up" principle, which helps you determine electron configuration. It says electrons with lower energy levels with tend to fill up first. Here's a diagram of the order.

[philipraj_1F]

You also need to know that there are exceptions to it with the 4s and 3d orbitals when the s orbitals lose an electron to the d orbitals.