# How many valence electrons does argon(Ar) have?

The atomic number of argon is 18. Argon is an inert element and its symbol is ‘Ar’. Argon atoms do not participate in the formation of any bonds. This article discusses in detail the valence electrons of argon(Ar) atom.

## How many electrons and protons does argon(Ar) have?

The nucleus is located in the center of the atom. Protons and neutrons are located in the nucleus. The atomic number of argon(Ar) is 18. The atomic number is the number of protons.

That is, the number of protons in argon(Ar) is eighteen. Electrons equal to protons are located in a circular shell outside the nucleus. That is, an argon(Ar) atom has a total of eighteen electrons.

## What are the valence electrons of argon(Ar)?

Argon(Ar) is an inert element. Argon is an element of group-18. The valence electron is the total number of electrons in the last orbit(shell). The total number of electrons in the last shell(final orbit) after the electron configuration of argon is called the valence electrons of argon.

The valence electrons determine the properties of the element and participate in the formation of bonds. The eighteenth element in the periodic table is argon(Ar). That is, the atom of the argon element has a total of eighteen electrons.

The electron configuration of argon shows that the last shell(final orbit) of argon has a total of eight electrons. That is, we can easily say that an argon atom has a total of eight valence electrons. There is an article on this site detailing the electron configuration of argon(Ar), you can read it if you want.

## How to determine the valence electron of argon(Ar)?

Now we will know how to easily determine the valence electron of argon(Ar). 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. There is an article published on this site detailing the electron configuration, you can read it if you want. However, this article briefly discusses electron configuration.

Scientist Niels Bohr was the first to give an idea of the atom’s orbit. He provided a model of the atom in 1913. The complete idea of the orbit is given there. The electrons of the atom revolve around the nucleus in a certain circular path. These circular paths are called orbit(shell). These orbits(shell) are expressed by n. [ n = 1,2 3 4 . . .]

K is the name of the first orbit(shell), L is the second, M is the third, N is the name of the fourth orbit(shell). The electron holding capacity of each orbit is 2n2. [Where, n = 1,2 3,4. . .]

Now,

• n = 1 for K orbit. The electron holding capacity of K orbit is 2n2 = 2 × 12 = 2 electrons.
• For L orbit, n = 2. The electron holding capacity of the L orbit is 2n2 = 2 × 22 = 8 electrons.
• n=3 for M orbit. The maximum electron holding capacity in M orbit is 2n2 = 2 × 32 = 18 electrons.

In addition to this method, electron configuration can be done through sub-orbits. The German physicist Aufbau first proposed an idea of electron configuration through sub-orbits. The Aufbau method is to do electron configuration through the sub-energy level.

These sub-orbitals are expressed by ‘l’. The Aufbau principle is that the electrons present in the atom will first complete the lowest energy orbital and then gradually continue to complete the higher energy orbital. These orbitals are named s, p, d, f. The electron holding capacity of these orbitals is s = 2, p = 6, d = 10 and f = 14.

However, valence electrons can be easily identified by arranging electrons according to the Bohr principle. Now we will learn how to determine the valence electron of argon(Ar).

### Step-1: Determining the total number of electrons

1st we need to know the total number of electrons in the argon(Ar) atom. To know the number of electrons, you need to know the number of protons in argon. And to know the number of protons, you need to know the atomic number of the argon 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 argon(Ar) 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 argon(Ar) atom. From the periodic table, we see that the atomic number of argon(Ar) is 18. That is, the argon(Ar) atom has a total of eighteen electrons.

### Step-2: Need to do electron configuration

Step 2 is very important. In this step, the electrons of argon(Ar) have to be arranged. We know that argon atoms have a total of eighteen electrons. The electron configuration of argon shows that there are two electrons in the K shell, eight in the L shell, and eight in the M shell(orbit).

That is, the first shell of argon(Ar) has two electrons, the second shell has eight electrons and the 3rd shell(orbit) has eight electrons. The number of electrons per shell of argon(Ar) is 2, 8, 8. The electron configuration of argon through the sub-orbit is 1s2 2s2 2p6 3s2 3p6.

### Step-3: Determining the valence shell(orbit) and calculate total electrons

The third step is to diagnose the valence shell(orbit). The last shell(final orbit) 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 argon(Ar) shows that the last shell of argon(Ar) has eight( 3s2 3p6) electrons. Therefore, the valence electrons of argon(Ar) are eight. In this way, the valence electrons of all the elements can be determined.

## Determination of the valency(valence) of argon(Ar)

The ability of one atom of an element to join another atom during the formation of a molecule is called valency(valence). The number of unpaired electrons in the last orbit of an element is the valency(valence) of that element.

The electron configuration of argon is 1s2 2s2 2p6 3s2 3p6. The electron configuration of argon shows that the argon atom has no unpaired electrons. There are eight electrons in the last orbit(shell) of an argon atom. Therefore, the valency of the argon atom is 0.

## Reasons for placing argon(Ar) in group-18 of the periodic table

The electron configuration of argon shows that the number of electrons in the last orbit(last shell) of the argon(Ar) atom is 8. We know that the number of electrons in the last orbit of an element is the number of groups in that element.

Accordingly, the group of argon is 8 but argon(Ar) is an inert element. All inert elements are placed in group number 18 in the periodic table. Therefore, argon(Ar) is placed in group-18 instead of group-8.

## Why is argon(Ar) an inert gas?

The elements in group-18 of the periodic table are inert gases. The inert gases of Group-18 are helium(He), neon(Ne), argon(Ar), krypton(Kr), xenon(Xe), and radon(Rn). We know that the element in group-18 is argon(Ar).

The electron configuration of argon shows that the orbit at the end of argon is filled with electrons. Argon does not want to exchange or share any electrons because the last orbit of argon is full of electrons. And argon does not form any compounds because it does not share any electrons.

They do not participate in chemical bonding and chemical reactions. For this, they are called inert elements. The inert elements are in the form of gases at normal temperatures. For this inert elements are called inert gases. Again for this same reason, inert gas is called a noble gas.