The outermost electron shell, also known as the valence shell, determines an element’s chemical behavior. The number of electrons residing within this shell dictates how readily an atom will interact with other atoms to form chemical bonds. For example, elements with nearly full valence shells tend to readily accept electrons, while those with only a few valence electrons tend to donate them.
A full valence shell imparts exceptional stability to an atom. This stability translates to a lack of reactivity, making such elements chemically inert. This inherent stability has historically led to their application in scenarios where inert environments are necessary, such as in lighting and protective atmospheres.
