what is aufbau principle
Answers
The aufbau principle states that in the ground state of an atom or ion, electrons fill atomic orbitals of the lowest available energy levels before occupying higher levels. For example, the 1s shell is filled before the 2s subshell is occupied. ... Aufbau is a German noun that means construction or "building-up".
The Aufbau Principle states that electrons fill orbitals of lower energy first before moving to higher energy orbitals.
Builting up by placing electrons in the lowest available orbitals until the total number of electrons added is equal to the atomic number. This is called Aufbau principle.
1. The German word 'Aufbau' means 'building up'.
2. The maximum number of electrons in any shell is 2n^2 where n is the principal quantum number.
Two general rules help us to predict electronic configurations.
1. Electrons are assigned to orbitals in order of increasing value of (n+l).
2.For sub-shells with the same value of (n+l), electrons are assigned first to the sub-shell with lower 'n'.