Which group of elements consists of colorless, odorless, and extremely unreactive gases?

The group of elements characterized as colorless, odorless, and extremely unreactive gases is the noble gases. This group includes helium, neon, argon, krypton, xenon, and radon. Noble gases have a full valence shell of electrons, meaning they have little tendency to react with other elements, which accounts for their lack of color and odor as well.

Due to their stable electron configuration, noble gases are nonpolar and do not readily form compounds under normal conditions, making them very unreactive. This contrasts sharply with halogens, which are quite reactive and are known for their colorful compounds and strong odors. Alkaline earth metals and alkali metals are both highly reactive; alkaline earth metals tend to react with water and air, while alkali metals react vigorously with water to form hydroxides and release hydrogen gas. Thus, noble gases stand out due to their unique physical properties and chemical stability.