What is a Valence Electron?

A key idea in chemistry is the concept of valence electrons, which is crucial to understanding how atoms behave, interact, and create chemical bonds. These electrons govern an atom’s chemical characteristics, reactivity, and bonding abilities. They are found at the outermost energy level, or shell, of the atom. So let’s see in detail about what is a valence Electron.

What is a Valence Electron

What is a Valence Electron?

Protons and neutrons make up the nucleus of an atom, which is encircled by an electron cloud. Electrons reside in energy levels or electron shells, each of which has a unique ability to accommodate them. Up to two electrons can fit in the innermost shell, up to eight in the second, and so on. When addressing valence electrons, the outermost shell, referred to as the valence shell, is of particular relevance.

The atomic number, which denotes the quantity of protons in an atom’s nucleus, is used to organise the periodic table, which is a fundamental component of chemistry. Additionally, it displays how electrons are arranged at different energy levels. Due to having the same quantity of valence electrons, the columns of the periodic table, also known as groups or families, have comparable chemical characteristics.

One valence electron, for instance, characterises the first group, which consists of hydrogen and alkali metals like lithium and sodium. The second group of elements, including magnesium and beryllium, also have two valence electrons. Because valence electrons in a group of elements are typically in a comparable number, this grouping tends to produce similar chemical behaviour.

Importance of Valence Electron

Valence electrons play a critical role in how atoms interact with one another to produce molecules and compounds. A stable electron configuration resembling that of noble gases, which have entire valence electron shells, is what atoms strive for. Noble gases, which belong to Group 18 of the periodic table, are stable. And chemically inert due to their full valence electron configurations.

Atoms that lack a full valence electron shell are more inclined to interact with other atoms in order to build one up and become stable. To achieve this state, they can lose, gain, or share electrons, resulting in a variety of chemical relationships.

Chemical Bonding And Valence Electron

Understanding chemical bonding, which involves the interaction of atoms to produce compounds, which involves valence electrons, is essential. Chemical bonding can be divided into three categories:

1) Ionic Bond : Atoms exchange valence electrons via ionic bonding to complete their valence shells. A positively charged ion is created when one atom contributes its electrons, and a negatively charged ion is created when an atom absorbs an electron. Ionic bonds are created as a result of the attraction between ions that have opposing charges.

2) Covalent Bond : Atoms form covalent bonds when they share valence electron pairs. By sharing, a connection is formed between the atoms of a molecule, holding it together. Nonmetal compounds frequently contain covalent connections.

3) Metallic Bond : Valence electrons in metals that are delocalized and free to move about the metal lattice exhibit metallic bonding. Electron mobility plays a role in the distinctive qualities of metals, including malleability and electrical conductivity.

Chemical Reactivity

The quantity of valence electrons an element has has a significant impact on how reactive it is. Chemical behaviour between elements that have a similar number of valence electrons tends to be analogous. For instance, Group 17 halogens, which are highly reactive nonmetals with seven valence electrons, are recognised for their propensity to gain an electron in order to complete a full valence shell.

Noble gases, in contrast, have full valence shells and are hence often chemically inert. Their modest propensity to form compounds with other elements is explained by their stability.


The building blocks of chemical bonding and the primary force in the synthesis of molecules and compounds are valence electrons. The reactivity of an atom and its capacity to form bonds with other atoms in order to attain a stable electron configuration are determined by these outermost electrons. Scientists can forecast the behaviour of elements, the kinds of bonds they form, and the characteristics of the ensuing compounds by comprehending the function of valence electrons and their distribution in the periodic table. Our understanding of the wide variety of chemicals that make up the world around us is supported by this information.

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