The terms valency and valence electrons are often used interchangeably even though there are various differences among them. In Chemistry, the literary concept of ‘valence’ is linked to capacity. The amount of bonds that an element or atom may make is referred to as its valency. Valence electrons, on the other hand, are the electrons that participate in the production of chemical bonds.
Valency vs Valence Electrons
The main difference between valency and valence electrons is that valency is the number of bonds formed around an atom, and it explains the bond formation between atoms. On the other hand, valence electrons are the electrons that help with chemical bonding and are ultimately associated with the elemental character.
An atom’s valency is the number of valence electrons that it can gain or lose during chemical processes. Valence inspired modern chemical bonding theories. The main group elements require a single valency, whilst transition metals have many valencies. The phrase, first used in 1868, is used to represent both the general power of the combination of an element and the numerical value of the power of combination.
Valence electrons are important because they provide detailed information on an element’s chemical characteristics, such as whether it is electronegative or electropositive in nature, as well as the bond order of a chemical compound, which determines the number of bonds that may form between two atoms. Photon energy can be accepted or emitted by a valence electron.
Comparison Table Between Valency and Valence Electrons
| Parameters of Comparison | Valency | Valence Electrons |
| Definition | Bonds in an atom that can form around it. | The electrons form chemical bonds. |
| Theory | The formation of bonds | The elemental character. |
| Application | Just a concept | Participates in the formation of bonds. |
| Transition Metal Elements | They have several valencies | It is expressed at the point of consideration in transition metals. |
| Example | The valency of nitrogen is 3 | Nitrogen has 5 valence electrons |
What is Valency?
The number of valence electrons in an element that participates in chemical reactions is referred to as its valency. When two or more components are joined in a certain 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. Each component has varied mixing possibilities.
In chemistry, valence, usually called valency, is the characteristic of an element that governs the number of other atoms with which an element’s atom can combine.
The explanation and systematization of valence posed a significant problem to nineteenth-century chemists. In the lack of a convincing theory of its origin, the majority of the work was directed toward developing empirical methods for establishing the valences of the components. The number of hydrogen atoms with which an element’s atom may mix or replace in a combination was used to calculate the element’s characteristic valence.
However, it became clear that the valences of several elements change in various compounds. The identification of the chemical bond of organic compounds with a pair of electrons possessed jointly by two atoms and serving to keep them together by the American chemist G.N. Lewis (1916) was the first big step in the creation of a good explanation of valence and chemical combination.
In chemistry, an element’s valence or valency is the measure of its ability to combine with other atoms to create chemical compounds or molecules.
Valency is a measure of an atom’s or molecule’s ability to combine. As a result, a single atom of one element can react and combine with a specific number of atoms of another element.
Electrons in an atom are grouped in several orbitals (shells) denoted by the letters K, L, M, N, and so on. Valence electrons are electrons found in an atom’s outermost shell/orbit. Valence electrons participate in any chemical reaction because the electrons in the outermost orbit often have higher energy than electrons in other orbits.
What are Valence Electrons?
A valence electron is an electron that is connected with an atom and can participate in the creation of a chemical bond. The number of valence electrons can affect the element’s chemical characteristics as well as its ability to connect with other elements. It should only be in the outermost electron shell of the main group element.
Because they have more energy than electrons in inner orbits, valence electrons are involved in the bulk of chemical reactions. Meanwhile, the presence of valence electrons contributes to determining the chemical properties of a certain component, such as its valence or valency, as well as the formation of bonds with other elements.
Changes in the atomic structure are restricted to electrons in the outer, i.e. valence electrons, regardless of whether the chemical connection between atoms is ionic, covalent, or metallic.
Ionization happens when one electron separates from the valence shell of its associated atom, resulting in the production of a positive ion.
The electrical conductivity of an element is also determined by valence electrons. Depending on the element’s nature, it can be a metal, a nonmetal, or a metalloid.
Main Differences Between Valency and Valence Electrons
- Valency refers to the number of atoms that surround an atom. On the other hand, valence electrons refer to the number of electrons that help chemical bonds.
- Valency helps describe the bonds that are present between atoms and elements. Valence electrons are connected to the elemental makeup of an element.
- Valency is a concept that doesn’t involve transitions whereas valence electrons form bonds.
- There are several valencies present in a transition metal while the valence electrons of a transition metal can be seen at the point of consideration.
- For example, the valency of nitrogen is 3 but the nitrogen has 5 valence electrons.
Conclusion
Valence electrons are the electrons in an element’s outermost shell, whereas valency electrons are the number of electrons that must be accepted or withdrawn to achieve the closest noble gas configuration. Typically, the electrons in the outermost shell contribute to the formation of chemical bonds.
References
- https://pubs.rsc.org/en/content/articlehtml/1973/dt/dt9730000838
- https://www.sciencedirect.com/science/article/pii/S0079678610000026