Aufbau Principle

[Shane_Yu_3K]

Hello,

Can someone explain what the Aufbau Principle is? I am a bit confused on this.

Thank you!

[Nandini_Parmar_1I]

It states that you have to first fill electrons in subshells of low energy and then once these are filled then electrons can fill subshells of high energy. So just how we write our electron configuration we have to fill a certain orbital before we can move onto another one.

[Caden Ciraulo 1J]

The Aufbau Principle states that in a ground state configuration of an atom, the electrons must fill lower energy levels before higher ones. This means you start from 1s to 2s and so on. This does also mean that 3d comes before 4s when writing the configuration, but 4s is filled first as it is lower energy.

[marisakuriyama1D]

The Aufbau principle basically states that orbitals of lowest energy are filled first (fill bottom to top). Thus, the Aufbau principle is a useful way to recognize if an atom is in an excited state. For example, if you look at an electron configuration which reads: 1s^1 2s^2... you can immediately tell that this atom is in an excited state because the e- configuration violates Aufau's principle - the 1s orbtial should be completely filled before filling the 2s orbital.

[VeronicaShepherd3B]

The Aufbau principle helps us understand how to fill electrons in their shells. We use the periodic table to help fill the electron shells in a sort of pattern.

[Samantha Melin 2E]

The Aufbau Principle states that electrons must fill subshells with the lowest energy first before filling subshells of higher energy. I will link a chart that shows the general rule for filling electron subshells along with some other helpful info down below.

https://www.chemicool.com/definition/au ... ciple.html

[Nathan Tran 1B]

Aufbau Principle essentially states that electrons will fill orbitals from the lowest energy state being the 1s orbital and fill up to higher energy orbitals.

[Junyong Wu]

I believe it is the procedure we followed to write the ground-state electron configuration, which can be summarized by Pauli exclusion principle and Hund's rule.

[Arjun_Anumula_3E]

Tha Aufbau principle is also called the building up principle, and it means that electrons will (generally) fill lower energy orbitals before filling higher energy ones. For example, 2s would be filled before electrons start to fill 2p.

[Kaira Shibata 1E]

It just means that orbitals with lower energies will be filled first. This is why there is an order of 1s, 2s,...etc.

[Julia Todorov 2F]

The Aufbau principle, or building up principle, states that the orbitals with lowest energy fill up first. This is why electron configurations won't be something like 1s1 2s2 2p3 3s2 in the ground state. The electrons want to fill the shells in order from lowest to highest energy

[Chris Van 2J]

The Aufbau Principle states how electrons fill up the lowest energy state first. This can be seen as we go from 1s to 2s to 2p etc.

[tashyavakil 2K]

This states you fill up lower energy orbitals first. So for example, you couldn't skip around from 2s to 2p without filling 2s first.