# How many valence electrons does scandium(Sc) have?

The 21th element in the periodic table is scandium. The element of group-3 is scandium and its symbol is ‘Sc’. Scandium participates in the formation of bonds through its valence electrons. This article discusses in detail the valence electrons of scandium(Sc).

## How many electrons and protons does scandium(Sc) have?

The nucleus is located in the center of the atom. Protons and neutrons are located in the nucleus. The atomic number of scandium(Sc) is 21. The atomic number is the number of protons.

That is, the number of protons in scandium twenty-one. Electrons equal to protons are located in a circular shell outside the nucleus. That is, a scandium atom has a total of twenty-one electrons.

## What are the valence electrons of scandium(Sc)?

The 1st element in group-3 is scandium(Sc).The elements in groups 3-12 are called transition elements. The valence electron is the total number of electrons in the last orbit. But in the case of transition elements, the valence electrons remain in the inner shell(orbit). This is because the electron configuration of the transition elements shows that the last electrons enter the d-orbital.

The valence electrons determine the properties of the element and participate in the formation of bonds. The 21st element in the periodic table is scandium(Sc). That is, the atom of the scandium element has a total of twenty-one electrons.

The electron configuration of scandium shows that the last shell(orbit) of scandium has a total of two electrons. But the electron configuration of scandium in the Aufbau method shows that its last electron(3d1) has entered the d-orbital. To determine the valence electron of a transition element, the last shell(orbit) electrons has to be calculated with the d-orbital electrons.

That is, we can easily say that scandium has three valence electrons. There is an article on this site detailing the electron configuration of scandium, you can read it if you want.

## How to determine the valence electron of scandium(Sc)?

Now we will know how to easily determine the valence electron of scandium(Sc). 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.

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.

The valence electrons of the transition element cannot be determined according to Bohr’s atomic model. This is because the valence electrons of the transition element are located in the inner shell.

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, the valence electron of the transition element can be easily determined according to the Aufbau principle. Now we will learn how to determine the valence electron of scandium(Sc).

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

1st we need to know the total number of electrons in the scandium atom. To know the number of electrons, you need to know the number of protons in scandium. And to know the number of protons, you need to know the atomic number of the scandium 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 scandium(Sc) 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 scandium atom. From the periodic table, we see that the atomic number of scandium(Sc) is 21. That is, the scandium atom has a total of twenty-one electrons.

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

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

That is, the first shell of scandium(Sc) has two electrons, the second shell has eight electrons, the 3rd shell has nine electrons and the 4th shell(last orbit) has two electrons. The number of electrons per shell of scandium(Sc) is 2, 8, 9, 2. The electron configuration of scandium(Sc) through the sub-orbit is 1s2 2s2 2p6 3s2 3p6 4s2 3d1.

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

The third step is to diagnose the valence shell(orbit). The last shell after the electron configuration is called the valence shell(orbit). The total number of electrons in a valence shell is called a valence electron.

But the valence electrons of the transition element are located in the inner orbit(shell). For the transition element, the valence electron has to be determined by adding the total electron of the d-orbital to the electron in the last orbit(shell) of the atom.

The electron configuration of scandium shows that the last shell of scandium has two(4s2) electrons and the d-orbital has a total of one electron(3d1). Therefore, the valence electrons of scandium(Sc) are three. In this way, the valence electrons of all the transition elements can be determined.

## How to determine the valency of scandium?

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 orbital after the electron configuration of an atom is called the valency of that element.

Valency is determined from the electron configuration of the element in the excited state. The electron configuration of scandium excited state is Sc*(21) = 1s2 2s2 2p6 3s2 3p6 4s1 3d1 4p1. The electron configuration of scandium shows that it has three unpaired(4s1 3d1 4p1) electrons. Therefore, the valency of scandium is 3.

## How many valence electrons does scandium ion(Sc3+) have?

The electron configuration of scandium shows that the last shell of scandium has two(4s2) electrons and the d-orbital has a total of one electron. In this case, the valency of scandium is 3. We know the details about this. The elements that have 1, 2, or three electrons in the last shell(orbit) donate the electrons in the last shell during bond formation.

The elements that form bonds by donating electrons are called cations. Scandium donates the electron of the last shell to form bonds and turns into scandium ion. That is, scandium is a cation element.

Sc – 3e → Sc3+

The electron configuration of scandium ion(Sc3+) is 1s2 2s2 2p6 3s2 3p6. The electron configuration of scandium ion(Sc3+) shows that scandium ion has only three shells and that shell has eight electrons (3s2 3p6). The electron configuration shows that the scandium atom has acquired the electron configuration of argon.

That is, in this case, the valence(valency) of the scandium ion is +3. Since the last shell(orbit) of a scandium ion has eight electrons, the valence electrons of scandium ion(Sc3+) are eight.

## Compound formation of scandium

Scandium participates in the formation of bonds through its valence electrons. We know that the valence electrons in scandium(Sc) 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 scandium 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 scandium atoms acquire the electron configuration of argon. Scandium oxide(Sc2O3) is formed by the exchange of electrons between two atoms of scandium and three atoms of oxygen. Scandium oxide(Sc2O3) is an ionic compound.