# How many valence electrons does boron(B) have?

The valence electrons of boron are three. Boron is the fifth element of the periodic table and the symbol is ‘B’. Boron participates in the formation of bonds through valence electrons. This article discusses in detail the valence electrons of boron.

## What are the valence electrons of boron(B)?

The total number of electrons in the last shell after the electron configuration of boron is called the valence electrons of boron. The valence electron is the total number of electrons in the last orbit.

The valence electrons determine the properties of the element and participate in the formation of bonds. The fifth element in the periodic table is the boron. That is, the atom of the boron element has a total of five electrons.

The electron configuration of boron shows that the last shell of boron has a total of three electrons. That is, we can easily say that the valence electrons of boron are three. There is an article on this site detailing the electron configuration of boron, you can read it if you want.

## How many electrons and protons does boron have?

The nucleus is located in the center of the atom. Protons and neutrons are located in the nucleus. The atomic number of boron is 5. The atomic number is the number of protons. That is, the number of protons in the boron is 5. Electrons equal to protons are located in a circular shell outside the nucleus. That is, boron atoms have 5 electrons.

## How to determine the valence electron of boron?

Now we will know how to easily determine the valence electron of boron. 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.

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 boron.

Step 1 – First we need to know the total number of electrons in the boron atom. To know the number of electrons, you need to know the number of protons in boron. And to know the number of protons, you need to know the atomic number of the boron 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 boron 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 boron atom. From the periodic table, we see that the atomic number of boron is 5. That is, a boron atom has a total of five electrons.

Step 2 – Step 2 is very important. In this step, the electrons of boron have to be arranged. We know that boron atoms have a total of five electrons. The electron configuration of boron shows that there are two electrons in the K shell and three in the L shell. That is, the first shell of boron has two and the second shell has three electrons. The electron configuration of boron through the sub-orbit is 1s2 2s2 2p1.

Step 3 – 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 boron shows that the last shell of boron has three electrons. Therefore, the valence electrons of boron are three. In this way, the valence electrons of all the elements can be determined.

## Determination of the valency of boron

The number of unpaired electrons in the last orbit of an element is the valency of that element. The electron configuration of boron in excited state is B*(5) = 1s2 2s1 2px1 2py1. The electron configuration of boron(B) shows that there are 3 unpaired electrons in the last orbit of boron. Therefore, the valency of the boron is 3.

## How many valence electrons of boron ion have?

After the electron configuration, the last shell of the boron atom has three electrons. In this case, both the valence and valence electrons of boron are 3. We know the details about this. The elements that have 1, 2, or three 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. That is, boron is a cation element. Boron donates the electrons of the last shell to form bonds and turns into boron ions.

B – 3e → B+3

The electron configuration of boron ions is 1s2. The electron configuration of boron ion shows that boron ion have only one shell and that shell has a total of two electrons. The electron configuration shows that the boron atom has acquired the electron configuration of helium. That is, in this case, the valence of the boron-ion is +3. Since the last shell of a boron-ion has two electrons, the valence electrons of a boron-ion are two.

## Compound formation of boron by valence electrons

Boron participates in the formation of bonds through its valence electrons. We know that the valence electrons in boron are three. This valence electron participates in the formation of bonds with atoms of other elements. The electron configuration of chlorine shows that the valence electrons of chlorine are seven.

The boron atom donates its valence electrons to the chlorine atom and the chlorine atom receives those electrons. As a result, chlorine acquires the electron configuration of argon and the boron atom acquires the electron configuration of helium. BCl3 is formed by the exchange of electrons between one atom of boron and three atoms of chlorine. BCl3 bonding is ionic bonding.