Difference Between Valency and Valence Electrons

Edited by Diffzy | Updated on: August 06, 2022

       

Difference Between Valency and Valence Electrons Difference Between Valency and Valence Electrons

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Introduction

The major distinction between valency and valence electrons may be found in their definitions: valence electrons are the electrons in an element's outermost shell, whereas valency electrons are the number of electrons that need to be accepted or withdrawn to achieve the nearest noble gas configuration. The electrons in the outermost shell are frequently involved in the formation of chemical bonds. The number of valence electrons in some atoms is equivalent to the number of valency electrons.

Valency vs. Valence Electrons

Even though the names Valency and Valence Electrons are fairly similar, there are some slight differences between them. The literary definition of the word "valence" in Chemistry is "capacity." The valency of an element is the number of bonds it can form in chemical terms. The electrons that are available to participate in this bonding are known as valence electrons. The main distinction between valency and valence electrons is that valency refers to the number of bonds that an atom or element can create, whereas valence electrons refer to the electrons that participate in these bond forms.

Element atoms have a natural tendency to mix with other element atoms. For the formation of a molecule, two or more atoms combine. For example, Sodium Chloride is formed when sodium and chlorine unite, and a molecule of hydrogen fluoride is formed when an atom of hydrogen and fluorine combine. Each atom has some capacity for mixing with other atoms. Valency refers to an element's ability to combine its constituent atoms. Among the different elements, Hydrogen and Chlorine have been considered to have the same valency. And that is why to determine the valency of other elements, comparison is made with hydrogen or chlorine.

The valency of an element is defined as the number of hydrogen or chlorine atoms that can combine with one atom of the element.

The valency of an element is also defined in the current language as follows:

The valency of an element refers to the number of electrons that are shared, lost, or acquired by an atom during a chemical process. The valence shell is the atom's outermost shell, and the electrons that make up that shell are known as 'valence electrons.' They determine the element's valency.

Valency is the number of bonds that an element or an atom may create, and valence electrons are the number of bonds that an element or an atom can form. Valence electrons, on the other hand, are the electrons that participate in the production of chemical bonds. The concept of valency is used to describe how atoms form bonds. The valence electrons, on the other hand, explain an atom's elemental character.

Difference Between Valency and Valence Electron in Tabular Form

Table: Valency vs. Valence Electrons
Parameters of comparison
Valency
Valence Electrons
Definition
The greatest number of electrons that an atom can lose is its valency.
in order of profits or shares
to achieve stability
The capacity of an atom to mix with another atom is known as valence.
Theory
The creation of bonds between atoms is explained by valency.
The concept of valency explains how atoms form bonds.
Representation
Without any integers, it is given as a number.
Before the number, a + or – integer is used to represent it.
Values
An atom's valency has only one value.
Valence of an atom can
have multiple values
 
Application
Valency is merely a concept that has nothing to do with electrons.
transitions.
The creation of bonds is aided by the presence of valence electrons.
Importance
The strength of the link between the atoms is determined by this parameter. The stronger the relationship, the higher the valency.
The valence electrons of an atom are responsible for chemical change and participate in it.

What is Valency?

The maximum number of univalent atoms (initially Hydrogen or Chlorine atoms) that may combine with an atom of the element under discussion, or with a fragment, or for which an atom of this element can be substituted, according to the IUPAC definition. It's worth noting that univalent atoms are taken into account because they only link up with one electron at a time. However, if a divalent atom such as Oxygen is utilized for this purpose, the valency will be equivalent to double the amount of Oxygen that participated in bond formation.

The number of valence electrons that an atom can gain or lose during chemical processes is known as its valency. In other terms, the valency of an element is the number of hydrogen atoms, chlorine atoms, or double the number of oxygen atoms that one atom of that element may combine with.

The number of valence electrons in an element that participates in chemical processes is referred to as its valency. When two or more components are joined in a specific mass proportion, a chemical compound is formed. When one atom of one element combines with a specified number of atoms of another element, a stable compound is created. All of the components have distinct mixing capabilities.

The number of valence electrons in an element that participates in chemical processes is referred to as its valency. When two or more components are joined in a specific mass proportion, a chemical compound is formed. When one atom of one element combines with a specified number of atoms of another element, a stable compound is created. All of the components have distinct mixing capabilities.

Metal Valuation

Metals have one, two, or three electrons in their valence shells (except hydrogen and helium, which are non-metals). Metals tend to lose their valence electrons and complete their octet in chemical reactions. Therefore, The number of electrons in a metallic element's valence shell is called its valency.

The valencies of elements in Groups 1, 2, and 13 of the periodic table are 1, 2, and 3, respectively, which correspond to the electron configuration in their final shell.

Consider the following scenario:

  • Sodium (salt) (Na)

Non-Metallic Valuation

A non-metal is defined as an element with 5 or 6 or 7 or 8 electrons in its valence shell. A non-metal requires 3 or 2 or 1 or 0 electrons to complete its octet. As a result, the valency of a non-metallic element is equal to the number of electrons in its outermost shell, which is 8.

Because elements in Groups 15, 16, and 17 of the periodic table have 5, 6, and 7 electrons in their final shells, non-metals valency is determined by determining the number of electrons required to complete their octet configuration.

Consider the following scenario:

  • nitrates (N)

The Value of Nobel Gases

Noble gases are elements in Group 18 of the periodic table that do not react because they have the most stable electronic configuration due to having the most valence electrons in their outer shell. Because every noble gas's outermost shell is filled, its valency is zero, and they do not lose or gain any electrons.

Consider the following scenario:

  • The color neon (Ne)

Various Types of Valency

Electrovalency and covalency are the two types of valency.

Electrovalency is the number of electrons lost or acquired by an element to achieve the closest inert gas configuration, i.e., stable configuration. Atoms of Li, Na, and K, for example, lose one electron, giving them an electrovalency of 1, while atoms of Mg, Ca, and Ba loses two electrons, giving them an electrovalency of 2. The atoms of O and S gain two electrons, resulting in a 2 electrovalency, while the atoms of Cl, Br, and I gain one electron, resulting in a 1 electrovalency.

Inert gas atoms have filled the outermost orbit. They don't lose, gain, or share electrons as a result. As a result, their valency is nil. The number of electrons shared by an atom of one element with another atom of the same or other element is referred to as its covalency.

For example, to make H2O, an oxygen atom shares two electrons with two H atoms. As a result, oxygen has a covalency of 2.

SiCl4 is formed when four silicon atoms share four electrons with four Cl atoms. Silicon has a covalency of four.

An atom attempts to complete its octet or duplet when building a stable molecule or during a chemical process. As a result, an atom's valency is defined as the number of electrons lost, acquired, or shared to complete its valence shell or octet.

What are Valence Electrons?

The electrons that participate in bond formation are known as valence electrons. Because they have numerous valencies, they are frequently found in the outermost shell of main group elements and can even be found in the closed shells of transition metals. The chemical features of each element are also defined by the valence electrons, which are arranged into columns in the periodic table based on the number of valence electrons.

When compared to atoms with more valence electrons in the outer shell, atoms with one or two more valence electrons than required to create noble gas (inert) electron configuration are particularly reactive. For example, if an element needs to give away its electrons to reach the noble gas electron configuration, it is easier to remove one or two electrons against the nuclear attraction than it is to remove more electrons. The same is true when electrons must be accepted to establish a noble gas arrangement. In this scenario, accepting a few electrons is easier than accepting a large number of electrons under strong electronegative forces.

Also, because valence electrons exist in an element's outermost shell, they can accept photons of energy and be thrilled to a higher energy level, and they can also release energy and be excited to a lower energy level. Because of the high kinetic energy, electrons that absorb a sufficient quantity of energy can be removed from the element during oxidation.

Valence electrons are the electrons in the outermost shell of an atomic nucleus. Valence electrons are significant because they give specific information about an element's chemical properties, such as whether it is naturally electronegative or electropositive, or the bond order of a chemical compound, which determines the number of bonds that can be formed between two atoms.

Thus, valence electrons are defined as: The number of electrons present in an element's outermost shell that participate in chemical bonding is referred to as valence electrons.

Lithium (Li), for example, has an atomic number of three. It has an electrical configuration of K = 2 and L = 1, which means that the K subshell is fully occupied and the L subshell, i.e. the outermost shell, only has one electron, which is the valence electron.

Regardless of whether the chemical contact between atoms is an ionic, covalent, or metallic link, changes in the atomic structure are confined to the electrons in the outermost shell, i.e., valence electrons.

A valence electron is an electron that is bonded to an atom and can be utilized to build a chemical connection; both atoms contribute one valence electron to form a shared pair in a single covalent bond. The number of valence electrons in an element can affect both its chemical properties and its capacity to interact with other elements:

  • In the main group element, a valence electron can only be in the outermost electron shell; an atom with a closed shell of valence electrons is chemically inert.
  • An atom with one or two valence electrons more than a closed shell is extremely reactive because the extra valence electrons are quickly removed to form a positive ion.
  • An atom with one or two valence electrons fewer than a closed shell is also extremely reactive because it tends to either obtain the missing valence electrons (forming a negative ion) or share valence electrons (thereby forming a covalent bond).
  • Like an electron in the inner shell, a valence electron can receive or release energy in the form of a photon. When an electron accumulates enough energy to migrate (jump) to an outer shell, this is known as atomic excitation.
  • When an electron breaks free from its related atom's valence shell, a positive ion is formed. When an electron loses energy (and hence emits a photon), it may migrate to a partially occupied inner shell.

Valence Electrons in an Atom: Determination

Although the number of shells increases as we progress through a group, the number of valence electrons does not.

The number of valence electrons rises by one with time, while the number of shells does not. The period number indicates the number of shells that surround an element's nucleus (row number).

Main Differences Between Valency and Valence Electrons In Points

  • Valency refers to an atom's or a group of atoms' ability to combine when creating a chemical bond (or the lowest number of electrons one element can share/lose/gain with another). It refers to the number of electrons received or lost by the atom/group to form a successful bond.
  • The attribute of an isolated atom is valency.
  • Valency refers to the number of electrons that an atom must receive or lose to reach its full outermost energy level.
  • Valence electrons refer to the total number of electrons in a system. It is the electrons in the atom's outermost shell ( by which an atom is capable of having a stable formation of bond or attaining a nearest noble gas configuration.)
  • The chemical characteristics of an element are determined by the existence of valence electrons.

Conclusion

Finally, the quantity of electrons an atom loses, gains, or shares with other atoms to achieve a stable configuration is known as valency. For instance, C (6) = 2,4

Carbon's valency will be four since it requires four extra electrons to achieve a stable state. On the other hand, the total number of electrons in an atom's outermost shell is known as the Valence electron. Carbon has four valence electrons because its outermost shell has four electrons. Nitrogen has a valency of 3 because it requires 3 more electrons to complete its octet, although it has 5 valence electrons.

The combining capacity of an element is known as valency. Valence electrons can be more than 4, but valency cannot be greater than 4. Also, keep in mind that an atom's valence electron count is always definite and may or may not be equal to its valency. However, the valency of an atom can vary and differ in distinct compounds.

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"Difference Between Valency and Valence Electrons." Diffzy.com, 2022. Fri. 12 Aug. 2022. <https://www.diffzy.com/article/difference-between-valency-and-valence-electrons-857>.



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