Inert gases, also known as noble gases, are a group of elements found in Group 18 of the periodic table. These gases include helium, neon, argon, krypton, xenon, and radon. They are characterized by their lack of reactivity due to having a full outer electron shell, which makes them stable and unlikely to form chemical bonds with other elements. Because of their non-reactive nature, inert gases have various applications. For example, helium is used in balloons and as a cooling medium in cryogenics, while argon is commonly used in welding to protect the molten metal from oxidation. Their unique properties make them valuable in scientific and industrial processes.