Elements that are chemically unreactive are noble gases. Noble gases are chemically unreactive, or inert, elements that reside in the right-hand column of the periodic table. In addition to classifying as inert, these substances share several common properties, which include a nonmetal structure, a lack of color and existence as single atoms.
Just as the ability to react makes some elements suited for certain purposes, lack of excitability makes noble gases ideal for specific applications. These elements are used primarily in balloons, light bulbs and advertising signs. When added to balloons and airships, noble gases make air less dense, which enables balloons and spacecraft to move upwards. The noble gas called argon is used primarily to generate light in light bulbs. Bulbs contain thin metal filaments, which would corrode and fade upon interacting with oxygen in the absence of argon. The unreactive nature of argon makes it ideal for preventing the filament from burning away. The noble gas called neon sees the most use in advertising signs. Neon lights up when electricity passes through it and appears in different colors depending on the temperature it reaches and the presence of other chemicals. Noble gases also have low boiling points and low densities compared to other elements in the periodic table.