What is the term for a full valence shell of electrons?

A full valence shell of electrons is referred to as an octet. In chemistry, atoms strive for a stable configuration, often achieving this through having eight electrons in their outermost shell. This stability is particularly important in the context of forming chemical bonds and is a central concept in understanding the behavior of elements in the periodic table.

The term "octet" arises from the fact that the maximum number of electrons in the outermost shell for many elements is eight, which aligns with the octet rule. This rule is foundational in predicting how atoms will interact and bond with one another.

While the other terms mention different configurations of electrons, they do not refer to the full valence shell that typically indicates stability in an atom's outer electronic structure. A "duet," for example, refers specifically to the stable configuration of lighter elements, like helium, that have only two electrons in their outer shell. A "quartet" and a "hexet" do not have standard definitions in the context of electron shells in chemistry. Thus, the term octet accurately describes the concept of a full valence shell for the majority of elements, especially those in the second and third periods of the periodic table.