Elements in which the s and p orbitals in the outermost shell are entirely filled are noble gases. These elements are located in Group 18 (or VIIIA) of the periodic table and include helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn).

Noble gases exhibit exceptional stability due to their complete valence electron configurations. Their outermost energy levels are filled with the maximum number of electrons allowed, resulting in a stable electron arrangement. These elements are highly unreactive, having little to no tendency to form chemical bonds with other elements. This inertness is why noble gases are often referred to as inert gases.