What is the name of the outermost shell of an atom that is most stable with eight electrons?

The name of the outermost shell of an atom that is most stable with eight electrons is called the valence shell. This concept is rooted in the octet rule, which states that atoms tend to gain, lose, or share electrons in such a way that they achieve a full outer shell with eight electrons, resulting in a more stable electron configuration.

The valence shell is crucial when considering chemical bonding and reactivity, as the electrons in this shell (known as valence electrons) are primarily involved in forming bonds with other atoms. Atoms strive for that stable octet, leading to various bonding behaviors that can influence the properties of elements and the formation of compounds.

Understanding the function of the valence shell helps clarify why certain elements behave similarly in reactions, as they share the same number of valence electrons. This stability explains why noble gases, which have full valence shells, are less reactive compared to other elements.