Chemically inert gas is mainly used to fill hot air and party balloons. Balloons filled with it float upwards and this phenomenon is achieved as helium gas is less dense than air Chemically inert In chemistry, the term chemically inert is used to describe a substance that is not chemically reactive. Most Group 8 or 18 elements that appear in the last column of the periodic table (Helium, Neon, Argon, Krypton, Xenon and Radon) are classified as inert (or unreactive). These elements are stable in their naturally occurring form (gaseous form) and they are called inert gases. The noble gases were previously
Incandescent light bulb sources are radiant efficiencies and efficacies. A similar chart in the article on luminous efficacy compares a broader array of light sources to one another. The spectrum emitted by a blackbody radiator at temperatures of incandescent bulbs does not match the sensitivity characteristics of the human eye. Most of the radiation is not in the range of wavelengths to which the eye is sensitive. Tungsten filaments radiate mostly infrared radiation at temperatures where they remain solid – below . Donald L. Klipstein explains it this way: "An ideal thermal radiator produces visible light most efficiently at temperatures around . Even