In terms of gases, which group is characterized by having a full valence shell?

The correct answer is noble gases, which are characterized by having a full valence shell. In the context of chemistry, the valence shell refers to the outermost shell of electrons in an atom, and a full valence shell typically means that the shell contains eight electrons, following the octet rule.

Noble gases, located in Group 18 of the periodic table, include helium, neon, argon, krypton, xenon, and radon. These gases are chemically inert or non-reactive due to their complete valence shells, which makes them stable and unlikely to form chemical bonds with other elements. This stability is the key reason why noble gases are often used in applications requiring non-reactive environments, such as in lighting or welding.

Other groups, such as halogens, alkali metals, and transition metals, do not possess full valence shells. Halogens, for example, have seven electrons in their outer shell and are highly reactive because they seek to gain an additional electron to achieve a full shell. Alkali metals have one electron in their outer shell, making them eager to lose that electron to attain a stable configuration. Transition metals, while they have various electron configurations, do not consistently have full valence shells either