How to Find the Valence Electrons for Aluminum (Al)?
The 13th element of the periodic table is aluminum. The element of group-13 is aluminum and its symbol is Al. Aluminum forms bonds through its valence electrons.
What are the valence electrons of aluminum?
The second element in group-13 is aluminum. The valence electron is the total number of electrons in the last orbit.
The total number of electrons in the last shell after the electron configuration of aluminum is called the valence electrons of aluminum(Al).

The valence electrons determine the properties of the element and participate in the formation of bonds.
How do you calculate the number of valence electrons in an aluminum atom?
The valence electron has to be determined by following a few steps. The electron configuration is one of them. It is not possible to determine the valence electron without electron configuration.
Knowing the electron configuration in the right way, it is very easy to determine the valence electrons of all the elements.
However, valence electrons can be easily identified by arranging electrons according to the Bohr atomic principle. Now we will learn how to determine the valence electron of aluminum(Al).
Step-1: Determining the total number of electrons in aluminum
1st we need to know the total number of electrons in the aluminum(Al) atom. To know the number of electrons, you need to know the number of protons in aluminum.
And to know the number of protons, you need to know the atomic number of the aluminum element.

To know the atomic number we need to take the help of a periodic table. It is necessary to know the atomic number of aluminum(Al) elements from the periodic table.
The atomic number is the number of protons. And electrons equal to protons are located outside the nucleus. That is, we can finally say that there are electrons equal to the atomic number in the aluminum atom.
From the periodic table, we see that the atomic number of aluminum is 13. That is, an aluminum(Al) atom has a total of thirteen electrons.
Step-2: Need to do electron configuration of aluminum
Step-2 is very important. In this step, the electrons of aluminum(Al) have to be arranged. We know that aluminum atoms have a total of thirteen electrons.
The electron configuration of the aluminum shows that there are two electrons in the K shell, eight in the L shell, and three in the M shell(orbit).

That is, the first shell of aluminum has two electrons, the second shell has eight electrons and the 3rd shell has three electrons.
Step-3: Determine the valence shell and calculate the total electrons
The third step is to diagnose the valence shell. The last shell after the electron configuration is called the valence shell.
The total number of electrons in a valence shell is called a valence electron.
The electron configuration of aluminum shows that the last shell of aluminum has three electrons. Therefore, the valence electrons of aluminum are three.
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What is the valency of aluminum?
The ability of one atom of an element to join another atom during the formation of a molecule is called valency(valence). There are some rules for diagnosing valency.
The number of electrons in an unpaired state in the last shell after the electron configuration of an atom is called the valency of that element.

The ground state electron configuration of aluminum is 1s2 2s2 2p6 3s1 3px1 3py1.
The electron configuration of the aluminum shows that it has three unpaired electrons in the last shell(3s1 3px1 3py1). Therefore, the valency of aluminum is 3.
How many valence electrons does aluminum ion(Al3+) have?
After the electron configuration, the last shell of the aluminum atom has three electrons. In this case, the valency of aluminum is 3. The elements that have 1, 2, or 3 electrons in the last shell donate the electrons in the last shell during bond formation.
The elements that form bonds by donating electrons are called cations. Aluminum donates the electron of the last shell to form bonds and turns into an aluminum ion(Al3+). That is, aluminum is a cation element.
Al – 3e– → Al3+
The electron configuration of aluminum ion(Al3+) is 1s2 2s2 2p6. The electron configuration of aluminum-ion shows that an aluminum ion has only two shells and the last shell has eight electrons.
The electron configuration shows that the aluminum ion(Al3+) has acquired the electron configuration of neon.
That is, in this case, the valency of the aluminum ion is +3. Since the last shell of an aluminum ion has eight electrons, the valence electrons of an aluminum ion(Al3+) are eight.
Compound formation of aluminum
Aluminum participates in the formation of bonds through its valence electrons. We know that the valence electrons in aluminum are three. This valence electron participates in the formation of bonds with atoms of other elements.
The electron configuration of oxygen shows that the valence electrons of oxygen are six. The aluminum atom donates its valence electrons to the oxygen atom and the oxygen atom receives those electrons.
As a result, oxygen acquires the electron configuration of neon, and aluminum atoms also acquire the electron configuration of neon.
Aluminum oxide(Al2O3) is formed by the exchange of electrons between two atoms of aluminum and three atoms of oxygen. Aluminum oxide (Al2O3) is ionic bonding.