Krypton

Krypton might share its name with Superman's home planet, but the real element is much more down to Earth — or rather, in Earth's atmosphere in tiny quantities. Discovered in 1898 by William Ramsay and Morris Travers, krypton gets its name from the Greek word 'kryptos,' meaning hidden, because it was so difficult to find.

Krypton is a noble gas that produces a brilliant white light when electricity passes through it. This property made it useful for high-speed photography flash lamps and airport runway lights. From 1960 to 1983, the official definition of the meter was based on the wavelength of light emitted by krypton-86 atoms — so this element literally defined how we measure length!

Krypton's symbol 'Kr' is a distinctive two-letter element in Spellement. While 'kr' is not a common English letter pair, it can be used with partial emphasis to contribute either 'k' or 'r' individually to word spellings, giving creative spellers an unusual but valuable tool.