[AntonioLao]

There are six noble gases found naturally comprising Group 18 of the Periodic Table of Chemical Elements and listed as: helium, neon, argon, krypton, xenon, and radon. Collectively, they are called the argonons indicating very low chemical reactivity. They are properly called inert gases. The 4th in the list, krypton, is widely believed in the comic world as a substance able to harm Superman but harmless to Spider-man, an earthling.

In addition to solid-state crystal LASERs, researchers believed in the early 1960s that gas LASERs are also feasible. However, initial attempts to make neon gas LASERs failed. Afterward, researchers at Bell Telephone Research Group were successful when they mixed neon gas with helium gas (both are noble) and then subjected the mixture to radio frequency pumping excitation and amplification. The helium-neon LASERs could produce invisible infrared (IR) coherent electromagnetic (EM) waves as well as visible red colored EM waves. Fortunately, unlike the solid ruby LASERs that produce pulses of energy, the helium-neon LASERs produce continuous coherent waves (CCW). This ability makes them useful for communications purposes. Furthermore, their extremely low energy outputs (thousandths of watts) make them safe and suitable for uses in school and laboratories. On the other hand, one of the most versatile noble gas LASERs is called the CO2 LASERs which are mixtures of 10% CO2, 10% nitrogen gas, but 80% helium gas. Other noble gas LASERs are ion LASERs of argon, krypton, neon, and xenon. Excimer gas LASERs made from krypton fluoride, xenon fluoride, argon fluoride, and xenon chloride can generate energy pulses of over a billion watts which are truly noble!