Elements that have no valence electrons are called noble gases or inert gases. These gases belong to Group 18 of the periodic table and include helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn).
Noble gases have full valence shells, meaning their outermost electron shell is completely filled with electrons. Helium has only 2 electrons in its outermost shell (valence level), while the rest of the noble gases have 8 electrons in their outermost shells, except for helium, which has only 2. This makes noble gases very stable and chemically unreactive under normal conditions. Their full valence shells make them less likely to gain or lose electrons, which is why they are often referred to as inert or noble.