Krypton

Uses

Krypton gas is used to fill certain specialty light bulbs, including some high-performance incandescent and fluorescent lamps, because it produces a brighter, whiter light than ordinary air-filled bulbs and allows thinner filaments to last longer. It’s also used in some photographic flash equipment and in some types of lasers. In construction, krypton is sometimes used instead of argon between the panes of high-efficiency double- or triple-glazed windows, since its lower thermal conductivity further reduces the amount of heat that passes through the glass.

For decades, krypton also played a foundational role in measurement science: from 1960 until 1983, the international definition of the meter was based on a precise wavelength of light emitted by krypton-86 atoms, replacing an older physical reference bar and giving scientists a far more reproducible standard, before the definition was updated again to be based on the speed of light.

History

Krypton was discovered in 1898 by Scottish chemist William Ramsay and English chemist Morris Travers, working in London. Having already identified argon a few years earlier, the pair suspected other unknown gases might be hiding in air and began evaporating liquid air and carefully examining the residues left behind. Among these residues they found a new, extremely unreactive gas that gave off a distinctive spectral signature under electrical discharge. They named it krypton, from the Greek word kryptos meaning hidden, a nod to how thoroughly it had escaped detection despite being present in every breath of air.