Noble gases occupy Group 18 and have filled or nearly filled valence shells, giving them low chemical reactivity under ordinary conditions. This makes them valuable for inert atmospheres, lighting, cryogenics, lasers and scientific instrumentation.
Overview
Argon is widely used for welding and metallurgical shielding, helium is indispensable in cryogenics and leak detection, and xenon supports lighting and ion propulsion. Radon is radioactive and primarily important as a health hazard. Oganesson is a superheavy synthetic element studied only in research.
Elements in this category
Using periodic-table categories in engineering
Periodic-table categories are useful for organizing trends, but they are not a substitute for material specifications. Engineering performance depends on purity, microstructure, processing history, temperature, environment and the way an element is combined into alloys or compounds.
Explore further: Periodic Table · Materials Library · Material Properties
