Group 18 Elements

Group 18 elements, also known as noble gases, include Helium (He), Neon (Ne), Argon (Ar), Krypton (Kr), Xenon (Xe), and Radon (Rn). They are called noble gases because they are extremely unreactive due to their completely filled outermost shell (ns²np⁶ configuration, except for He which has 1s²). This stable electron configuration makes them inert under normal conditions. However, under extreme conditions, some heavier noble gases like Xenon can form compounds. Noble gases are colorless, odorless, and exist as monatomic gases at room temperature.