Valenceelectron

Valence electrons are the electrons in the outermost shell of an atom. These electrons are involved in chemical bonding, as they can be shared, lost, or gained by an atom when it interacts with other atoms. The number of valence electrons an atom possesses determines its chemical properties and how it will react with other elements. Elements in the same group of the periodic table typically have the same number of valence electrons, which explains why they exhibit similar chemical behaviors. For instance, alkali metals, found in Group 1, all have one valence electron, making them highly reactive and prone to losing that electron to form a positive ion. Noble gases, on the other hand, are located in Group 18 and generally have eight valence electrons (except for helium, which has two). This full outer shell makes them very stable and unreactive. Understanding valence electrons is fundamental to comprehending chemical reactions, the formation of molecules, and the organization of the periodic table. The octet rule, which states that atoms tend to gain, lose, or share electrons until they are surrounded by eight valence electrons, is a key concept in predicting chemical bonding.