How to make Orbital Diagram or Orbital filling diagram?
Home > How to draw an Orbital diagram?
An orbital diagram is simply a pictorial representation of the arrangement of electrons in the orbital of an atom, it shows the electrons in the form of arrows, and also, indicates the spin of electrons.
In this article, we will discuss – How to draw an Orbital diagram or an Orbital notation configuration?
How to Draw Orbital Diagrams?
The orbital diagram simply represents the arrangement of electrons in the different orbitals of an atom, it uses an arrow to represent the electrons, every orbital(one box) contains a maximum of 2 electrons.
There are three rules followed for constructing the orbital diagram for an atom.
(1). Aufbau’s principle: This rule state that the lower energy orbital will be filled before the higher energy orbital, for example – the 1s orbital will fill before the 2s orbital.
(2). Hund’s rule: This rule state that each orbital of a given subshell should be filled with one electron each before pairing them. That means “Each orbital gets one electron first, before adding the second electron to the orbital”.
(3). Pauli Exclusion Principle: This rule state that, no two electrons can occupy the same orbital with the same spin. That means “One must be spin up (↑) and one must be spin down (↓)”.
If you understand the above rules then constructing the orbital diagram or orbital notation for any atom is super easy.
Basics of Orbital diagram:
There are different types of orbitals – s, p, d, and, f. These orbitals contain a number of boxes that can hold a number of electrons. Let’s see.
Each box will hold a maximum of 2 electrons with opposite spin.
 S orbital contains 1 box that can hold a maximum of 2 electrons.
 P orbital contains 3 boxes that can hold a maximum of 6 electrons.
 D orbital contains 5 boxes that can hold a maximum of 10 electrons.
 F orbital contains 7 boxes that can hold a maximum of 14 electrons.
The orbital diagram will be filled in the same order as described by the Aufbau principle.
“The Aufbau principle states that electrons will inhabit the lowestenergy orbitals first. This means that electrons can only enter higherenergy orbitals after lowerenergy orbitals have been entirely filled.”
We have a diagonal rule for electron filling order in the different subshells using the Aufbau principle.
So, the order in which the orbitals are filled with electrons from lower energy to higher energy is –
1s < 2s < 2p < 3s < 3p < 4s < 3d < 4p < 5s < 4d < 5p < 6s < 4f < 5d < 6p < 7s < 5f < 6d < 7p and so on.
Trick: you can learn the order of the orbital box diagram and then fill out the electrons in it.
How to write an Orbital diagram/notation for any atom?
To draw the orbital diagram for an atom, follow these basic steps
 Find the number of electrons in an atom.
 Write the electron configuration for an atom to determine which orbitals should be filled.
 Fill the electrons in empty boxes using three principles – Aufbau, Hund’s, and Pauli Exclusion.
Let’s take an example of the Nitrogen atom to understand the concept of the making of filling the orbital diagram.
How to draw an Orbital diagram for Nitrogen?
We know that the nitrogen atom has a total of 7 electrons that need to be placed into orbitals, now for drawing its orbital diagram, we need to show its electrons in form of an arrow in different boxes using Aufbau, Hund’s, and Pauli’s exclusion rule.
 Nitrogen has a total of 7 electrons and its electron configuration is 1s^{2}2s^{2}2p^{3}.
 As per the Aufbau rule, the electrons will be filled into 1s orbital first then 2s, then 2p…so on.
 1s orbital contains 1 box, 2s orbital also contains 1 box and 2p orbital contains 3 boxes. Also, one box can hold up to two electrons.
 Therefore, the first two electrons of nitrogen will go in the 1s orbital, and the next two will go in the 2s orbital, now we are left with 3 electrons.
 These 3 electrons will go in the 2p orbital, since, the 2p orbital has 3 boxes, so, these electrons will be filled using Hund’s rule. (Each box gets one electron first).
Let’s take one more example to understand the procedure of drawing the orbital diagram for an atom.
How to draw an Orbital diagram for Potassium?
We know the potassium has a total of 19 electrons that need to be placed into orbitals, now for drawing its orbital diagram, we need to show its electrons in form of an arrow in different boxes using Aufbau, Hund’s, and Pauli’s exclusion rule.
 Potassium has a total of 19 electrons and its electron configuration is 1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{1}.
 As per the Aufbau rule, the electrons will be filled into 1s orbital first then 2s, then 2p…so on.
 1s orbital contains 1 box, 2s orbital also contains 1 box, 2p orbital contains 3 boxes, 3s orbital contains 1 box, 3p orbital contains 3 boxes, and 4s orbital contains 1 box. Also, one box can hold up to two electrons.
 Therefore, the first two electrons of potassium will go into the 1s orbital, the next two will go into the 2s orbital, and after that, the next six electrons will go into the 2p orbital, since, the 2p orbital has 3 boxes.
 After that, the next two electrons will go in the 3s orbital, and the next six electrons will enter the 3p orbital. Now, the 3p orbital is full.
 Therefore, the remaining one electron will go in 4s orbital in the clockwise direction. (↑)
Take one more example of the atom – Chlorine (Atomic no. 17).
How to draw an Orbital diagram for Chlorine?
 Chlorine has a total of 17 electrons and it’s electron configuration is 1s^{2}2s^{2}2p^{6}3s^{2}3p^{5}.
 As per the Aufbau rule, the electrons will be filled into 1s orbital first then 2s, then 2p…so on.
 1s orbital contains 1 box, 2s orbital also contains 1 box, 2p orbital contains 3 boxes, 3s orbital contains 1 box and 3p orbital contains 3 boxes.
 Therefore, the first two electrons of chlorine will go into the 1s orbital, the next two will go into the 2s orbital, and after that, the next six electrons will go into the 2p orbital, since, the 2p orbital has 3 boxes.
 After that, the next two electrons will go into the 3s orbital, and the remaining five electrons will enter the 3p orbital, since, the 3p orbital has 3 boxes, so, these electrons will be filled using Hund’s rule. (Each box gets one electron first, then start pairing).
At last, Let’s try to construct one more orbital diagram for atom – Sodium (Atomic no. 11).
How to draw an Orbital diagram for Sodium?
 Sodium has a total of 11 electrons and its electron configuration is 1s^{2}2s^{2}2p^{6}3s^{1}.
 As per the Aufbau rule, the electrons will be filled into 1s orbital first then 2s, then 2p…so on.
 1s orbital contains 1 box, 2s orbital also contains 1 box, 2p orbital contains 3 boxes, and 3s orbital contains 1 box.
 Therefore, the first two electrons of the Sodium atom will go into the 1s orbital, the next two will go into the 2s orbital, after that, the next six electrons will go into the 2p orbital, since, the 2p orbital has 3 boxes, so, these electrons will be filled using Hund’s rule. (Each box gets one electron first, then start pairing).
 After filling these orbitals, we are still left with 1 electron, this will go in 3s orbital.
What is the difference between an Electron configuration or an Orbital diagram?
The main difference between the orbital diagram and electron configuration is an orbital diagram shows electrons in form of arrows whereas an electron configuration shows electrons in form of numbers. Also, the orbital diagram shows details on the spin of electrons whereas the electron configuration doesn’t show it.
Both these follow the Aufbau principle (Diagonal rule).
Take a look at the Electron configuration vs Orbital diagram for Nitrogen.
Please read out the articles on the Orbital diagram and electron configuration for various atoms to understand the concept better.
 Nitrogen orbital diagram and electron configuration
 Oxygen orbital diagram and electron configuration
 Carbon orbital diagram and electron configuration
 Fluorine orbital diagram and electron configuration
 Neon orbital diagram and electron configuration
 Boron orbital diagram and electron configuration
 Sodium orbital diagram and electron configuration
 Magnesium orbital diagram and electron configuration
 Aluminum orbital diagram and electron configuration
 Silicon orbital diagram and electron configuration
 Phosphorous orbital diagram and electron configuration
 Sulfur orbital diagram and electron configuration
 Chlorine orbital diagram and electron configuration
 Argon orbital diagram and electron configuration
 Potassium orbital diagram and electron configuration
 Calcium orbital diagram and electron configuration
 Beryllium orbital diagram and electron configuration
 Lithium orbital diagram and electron configuration
Also Read: How to draw Bohr model diagram of an atom
FAQ
How Electron is represented in the Orbital diagram?The electron is shown in form of arrows in the orbital box diagram.

How do know the number of boxes in each orbital?There are 4 types of orbital – s, p, d, and f.

How unpaired electrons are represented in the Orbital box diagram?When the orbital box contains only one electron, it is said to be an unpaired electron box. The unpaired electron is always represented with spinup arrows (↑), it doesn’t contain a spindown arrow(↓). 
What is the order of filling electrons in the Orbital boxes diagram?The orbital diagram will be filled in the same order as described by the Aufbau principle. The order in which the orbitals are filled with electrons from lower energy to higher energy is –
The above order means –

Summary
 The orbital diagram is drawn by using three rules – Aufbau’s rule, Hund’s rule, and Pauli’s exclusion rule.
 For drawing the orbital diagram or orbital notation, first, find the number of electrons in an atom then write its electron configuration to determine which orbital should be filled.
 And then fill the electrons in empty orbital boxes using three rules.
 The electron is always filled in an orbital box starting with a spinup arrow(↑).
 Orbital configuration represents electrons in form of the arrow(↑↓) and Electron configuration represents electrons in form of numbers.
 One box of orbital diagrams can hold up to 2 electrons.
 Both the Orbital configuration and Electron configuration follow the Aufbau principle. That means the lower energy orbital will be filled first(i.e. 1s orbital is filled before the 2s orbital).
Related Posts:
 How to write Electron Configuration for any element  All…
 Calcium Orbital diagram, Electron configuration, and Valence…
 Sulfur Orbital diagram, Electron configuration, and Valence…
 Phosphorus Orbital diagram, Electron configuration, and…
 Silicon Orbital diagram, Electron configuration, and Valence…
 Chlorine Orbital diagram, Electron configuration, and…
 Potassium Orbital diagram, Electron configuration, and…
 Argon Orbital diagram, Electron configuration, and Valence…
 Aluminum Orbital diagram, Electron configuration, and…
 Magnesium Orbital diagram, Electron configuration, and…