Filling of Atomic Orbitals
How atomic orbital are filled with electrons? the answer to this is very important to find the electron configuration of various atoms various rules which help in filling of atomic orbital are,
Aufbau Principle
The principle states that the electrons will occupy the orbits with lower energy and then the orbits with higher energy levels. The principle gets its name from the Greek word “Aufbeen” which means building up. As per the following principle the electrons are arranged in the order as shown in the following image.
Pauli Exclusion Principle
The Pauli Exclusion Principle states that a maximum of two electrons can fit into an orbit with opposite spins. It is based on the concept that if two electrons carry equal azimuthal numbers then they will have opposite spins in the orbit.
Hund’s Rule
The rule states that every orbit is initially occupied by a single electron before a second electron fills the orbit. It’s the rule that determines the order of electrons in the sub-shell.
The following image shows the correct way to fill electrons in a sub-shell.
Electron Configuration
Electron Configuration of an element tells us how electrons are filled inside various orbitals of the atom. The distribution of electrons inside various orbital of atoms is very useful in explaining various properties of the atoms and their combination with other atoms. The electron configuration of the N (the most common element in the Earth’s atmosphere) is 1s2 2s2 2p4 as it has 7 electrons which are arranged in order as 2 is 1s orbital, 2 in 2s orbital, and 3 in 2p orbital.
Let’s have a look at how electrons are arranged around a nucleus for other atoms which rules are useful in achieving the right electron configuration and other in this article.