An element in which the highest occupied s and p sublevels are filled is called a noble gas or an inert gas.
The noble gases are a group of elements in the periodic table that are located in the far right column, these elements are helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn).
The noble gases have a full valence shell, meaning that their outermost electron shell is filled with the maximum number of electrons. This gives them a stable electron configuration and makes them unreactive with other elements. Because of this, they are also referred to as "inert" gases.
Noble gases are chemically unreactive due to their filled valence shells, which makes them a unique group of elements and they are used in a wide range of industrial and medical applications.