Aluminum (Al) Orbital diagram, Electron configuration, and Valence electrons

The electron configuration of Aluminum can be found using the Aufbau principle.

Aufbau Principle:

• The word ‘Aufbau’ in German means ‘building up’.
• The Aufbau rule simply gives the order of electrons filling in the orbital of an atom in its ground state.
• It states that the orbital with the lowest energy level will be filled first before those with high energy levels. In short, the electrons will be filled in the orbital in order of their increasing energies.
• For example, the 1s orbital will be filled first with electrons before the 2s orbital.

Simply understand that there are commonly four different types of subshells – s, p, d, and, f.

These subshells can hold a maximum number of electrons on the basis of a formula, 2(2l + 1) where ‘l’ is the azimuthal quantum number.

Value of ‘l’ for different subshells.

Subshells	Value of ‘l’	Maximum number of electrons, 2(2l + 1)	Number of orbitals in the subshell
s	0	2	1
p	1	6	3
d	2	10	5
f	3	14	7

So, in short, the s subshell can hold a maximum of 2 electrons(1 orbital), the p subshell can hold 6 electrons(3 orbitals), the d subshell can hold 10 electrons(5 orbitals), and the f subshell can hold at most 14 electrons(7 orbitals).

Now, the electron configuration of an atom can be built by filling the electrons in a lower energy subshell first then higher, higher, and higher.

Generally, (n + l) rule is used to predict the energy level of subshells.

n = principle quantum number

l = Azimuthal quantum number

⇒ Lower the value of (n + l) for an subshell, the lower its energy, hence, it will be filled first with electrons.

⇒ For two different subshells having same (n + l) value, then the subshell with lower value of n has lower energy.

So, all these are basics of How filling of electrons will be done in different subshells, obviously, you don’t have so much time for writing electron configuration by using so many rules.

Therefore, 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.

Aluminum Electron configuration using the Aufbau Principle

• An Aluminum atom is a neutral atom that has an atomic number of 13 which implies it has a total of 13 electrons.
• As per the Aufbau rule, the electrons will be filled into 1s orbital first then 2s, then 2p…so on.
• Now, for the electron configuration of Aluminum, the first 2 electrons will go in 1s orbital since s subshell can hold a maximum of 2 electrons.
• The next two electrons will go into the 2s orbital, after that, the next 6 electrons will go into the 2p orbital since the p subshell can hold up to 6 electrons.
• The next two electrons will go into the 3s orbital, and after that, the remaining one electron will go into 3p orbital.
• Therefore, the electron configuration of Aluminum will be 1s²2s²2p⁶3s²3p¹.

Aluminum (Al) Electron Configuration

Check – Electron configuration calculator to count the electron configuration for any atom

Orbital diagram for Aluminum

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 drawing 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 Aluminum 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 also be filled with the same order as described by the Aufbau principle. (1s < 2s < 2p < 3s……and so on.)

Also check –

• Orbital diagram calculator
• Orbital diagram for all elements in the periodic table

What is the Orbital diagram for Aluminum?

We know the electron configuration of Aluminum is 1s²2s²2p⁶3s²3p¹, now for drawing its orbital diagram, we need to show its electrons in form of an arrow in different boxes using Hund’s and Pauli’s exclusion rule.

• The orbital diagram of Aluminum contains 1s orbital, 2s orbital, 2p orbital, 3s orbital, and 3p orbital. 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.
• Aluminum has a total of 13 electrons and one box can hold up to two electrons.
• Therefore, the first two electrons 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 one electron will enter the 3p orbital in a clockwise direction(↑).

Aluminum Orbital diagram/notation

Electron configuration Vs Orbital diagram for Aluminum

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).

Also Read:–

• How to find the Electron configuration for any elements?
• How to draw the Orbital diagram for an atom?

Electron configuration for Aluminum via Bohr model (Orbit)

Bohr model describes the visual representation of orbiting electrons around the small nucleus. It used different electron shells such as K, L, M, N…so on.

These electron shells hold a specific number of electrons that can be calculated via the 2n² formula where n represents the shell number.

Electron shells	Shell number (n)	Max. number of electrons (2n2)
K	1	2
L	2	8
M	3	18
N	4	32

So, K is the first shell or orbit that can hold up to 2 electrons, L is the 2nd shell which can hold up to 8 electrons, M is the third shell that can hold up to 18 electrons, and N is the fourth shell that can hold up to 32 electrons.

Now, Aluminum has an atomic number of 13 and it contains a total number of 13 electrons. Hence, 2 electrons will go in the first shell(K), 8 electrons will go in the second shell(L), and the remaining three electrons will go in the third shell(M).

Therefore, the electrons per shell for Aluminum are 2, 8, 3, hence, we can say, based on the shell, the electronic configuration of the Aluminum atom is [2, 8, 3].

Also check – How to draw Bohr model of Aluminum atom

Aluminum Valence electrons

Valence electrons are the outermost electrons present in the outermost shell of an atom. They have more energy, hence, they are part of most chemical reactions.

We can find valence electrons of an atom either by knowing its periodic group number or its electron configuration. Both these ways are super easy.

Finding Aluminum Valence electrons through the Group number

For neutral atoms, the valence electrons of an atom will be equal to its main periodic group number. However, for transition metals, the process of finding valence electrons is complicated.

Now, for determining the valence electron for the Aluminum atom, look at the periodic table and find its Group number. The group number can be found from its column on the periodic table.

So, the number of valence electrons in Aluminum is 3. Since it belongs to Group 13th or 3A in the Periodic table.

Finding Aluminum Valence electrons through the Electron configuration or Bohr model

We know, the electron configuration of the Aluminum atom is 1s²2s²2p⁶3s²3p¹, and valence electrons are those electrons found in the outer shell of an atom.

This electron configuration of Aluminum shows that the outer shell of Aluminum has 3 electrons(3s²3p¹), hence, the number of valence electrons in the Aluminum atom is 3.

Also, we know, the electron configuration of Aluminum, based on the shells is [2, 8, 3], which means, that two electrons are present in the first shell, eight electrons are present in the 2nd shell, and three electrons are present in the third shell or outer shell.

Hence, the electrons found in the 3rd shell of the Aluminum atom are its valence electrons because it is the outermost shell also called the valence shell.

The 3rd shell or outer shell of the Aluminum atom contains 3 electrons, therefore, the number of valence electrons in the Aluminum atom is 3.

Check – Valence electron calculator to calculate the number of valence electrons for any atom

Electron configuration, Valence electrons, and Orbital diagram of Aluminum in tabular form

Name of atom	Aluminum (Al)
Number of electrons	13
Number of electrons per shell	[2, 8, 3]
Number of valence electrons	3
Electron configuration	1s22s22p63s23p1 or [Ne] 3s23p1
Orbital diagram	Consists of five orbitals – 1s, 2s, 2p, 3s, and 3p.

Also read:

• 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
• 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

FAQ

What are the Ground state and Excited-state Electron configurations of Aluminum? There is a simple difference between Ground state and Excited-state configuration. The ground state configuration of an atom is the same as its regular electron configuration in which electrons remain in the lowest possible energy. So, the ground-state electron configuration for the Aluminum atom is 1s22s22p63s23p1. The excited-state configuration of an atom is different from the regular configuration of an atom, this occurs, when an electron is excited and jumps into a higher orbital. The excited-state electron configuration for Aluminum is 1s22s22p63s24s1. “for the first excited state, $3p\to 4s$ transition, changing the valence electron configuration from $3s^{2}3p^1$ to $3s^{2}4s^{\mathrm{1“.}}$

What is the shorthand electron configuration of Aluminum? The shorthand electron configuration for the Aluminum atom is [Ne] 3s23p1. ∴ [Ne] electron configuration is 1s22s22p6.

Which element has the 1s22s22p63s23p1 Electron configuration? Element with electron configuration 1s22s22p63s23p1 is Aluminum (Al) which has the atomic number of 13.

How many valence electrons does Aluminum have? The Aluminum atom has 3 valence electrons in its outermost or valence shell. Aluminum is belonged to group 13th or 3A and has the atomic number of 13.

What is the orbital diagram for Aluminum (Al)? The orbital diagram for Aluminum is drawn with 5 orbitals. The orbitals are 1s, 2s, 2p, 3s, and 3p. The Aluminum orbital diagram contains 2 electrons in the 1s orbital, 2 electrons in the 2s orbital, the six electrons in the 2p orbital, the two electrons in the 3s orbital, and the remaining one electron in the 3p orbital. An orbital diagram for a ground-state electron configuration of an Aluminum atom is shown below-

What is the electron configuration of the Al3+ ion? We know, in general, that the electron configuration of Aluminum (Al) is 1s22s22p63s23p1. Now, in the Al3+ ion, the positive charge means, Aluminum loses three electrons. Therefore, to write the electron configuration of the Al3+ ion, we have to remove three electrons from the configuration of Aluminum (Al). ∴ The resulting electron configuration for the Al3+ will be 1s22s22p6. It resembles the configuration of the nearest inert gas i.e Neon.

Properties of Aluminum

• It has a great ability to reflect light.
• It appears as silvery grey metallic.
• It has a boiling point of 2470 °C and melting of 660.32 °C.
• Its electronegativity value is 1.61 and its oxidation state varies from -2 to +3.
• It has a face-centered cubic crystal structure.
• It has three electrons beyond a stable noble gas configuration.
• It is paramagnetic in nature
• It is nor-metallic and ductile in nature.

Summary

• The electron configuration of Aluminum in terms of the shell or orbit is [2, 8, 3].
• The ground-state electron configuration of the Aluminum (Al) atom is 1s²2s²2p⁶3s²3p¹. And for the excited state, it is 1s²2s²2p⁶3s²4s¹.
• The shorthand electron configuration for Aluminum is [Ne] 3s²3p¹.
• The electron configuration for the Aluminum ion (Al³⁺) is 1s²2s²2p⁶.
• The number of valence electrons available for the Aluminum atom is 3. Aluminum is situated in Group 13th or 3A and has an atomic number of 13.
• The first shell of Aluminum has 2 electrons and the outer shell or valence shell of Aluminum has 3 electrons, hence, the number of valence electrons in the Aluminum atom is 3.
• The orbital diagram for Aluminum is drawn by following three principles – the Aufbau principle, Hund’s principle, and Pauli’s exclusion principle.
• The Aluminum orbital diagram comprises five orbitals. The five orbitals are 1s, 2s, 2p, 3s, and 3p.
• The first two electrons will go in the 1s orbital, the next two in the 2s orbital, the next six in the 2p orbital, the next two electrons in the 3s orbital, and the remaining one electron in the 3p orbital.