Krypton gas glowing greenish-blue in a discharge tube
8 December 2023
This post is about the element, not Superman’s home planet.
Krypton is colorless and odorless noble gas with atomic number 36 and the symbol Kr. It is used in various lighting applications, such as flashes for high-speed photography and luminous signs, for which, when mixed with mercury vapor, it gives off a greenish-blue light.
The element was discovered by chemists William Ramsay and Morris Travers in 1898. They named it after the Greek κρυπτός, or kryptos, meaning secret or hidden because of the difficulty in detecting it. The discovery was first announced at a meeting of the French Academy of Sciences on 6 June 1898, as reported by the Westminster Gazette the following day:
At yesterday’s meeting of the Academy of Sciences in Paris M. Berthelot read a letter from Professor Ramsay, the co-discoverer with Lord Rayleigh of argon, giving the first announcement of another discovery of the same nature. The new gas he proposes to call krypton. The discovery was effected, like that of argon, by the aid of the spectroscope. The presence of krypton was detected by the existence in the spectrum of a green line, which M. Berthelot saw yesterday (the Times correspondent notes) in a minute tube containing the two-millionth of a pound which Professor Ramsay has sent with his letter. According to the description forwarded to M. Berthelot, krypton belongs, not to the argon, but to the helium family, and its density is somewhat greater than oxygen. It appears to be a simple body and monatomic.
Ramsay and Travers read their paper on the discovery at the Royal Society of London meeting on 9 June 1898:
From what has preceded, it may be concluded that the atmosphere contains a hitherto undiscovered gas with a characteristic spectrum, heavier than argon, and less volatile than nitrogen, oxygen, and argon; the ratio of its specific heats would lead to the inference that it is monatomic, and therefore an element. If this conclusion turns out to be well substantiated, we propose to call it “krypton,” or “hidden.” Its symbol would then be Kr.
But this was not the first time that Ramsay had attempted to use the name krypton. In 1895, he detected what he thought to be a new element, and his laboratory notes show that he intended to call it krypton. But it turned out that what Ramsay had found was not a new element but rather helium, which had previously been detected in the spectra of the sun and in volcanic effluvia. But Ramsay’s disappointment in this case was assuaged by his being the first to isolate helium in a laboratory.
Krypton as the name of Superman’s home planet is the invention of Jerry Siegel and Joe Shuster and is first mentioned in Action Comics #1 of June 1938, the issue in which Superman makes his debut.
Sources:
Jensen, William B. “Why Helium Ends in “-ium.” Journal of Chemical Education, 81.7, July 2004, 944. DOI: 10.1021/ed081p944.
“Krypton and Dynammon.” The Westminster Gazette, 7 June 1898, 4/2. The British Newspaper Archive.
Miśkowiec, Pawel. “Name Game: The Naming History of the Chemical Elements: Part 2—Turbulent Nineteenth Century.” Foundations of Chemistry, 8 December 2022. DOI: 10.1007/s10698-022-09451-w.
Oxford English Dictionary, second edition, 1989, s.v. krypton, n.
Ramsay, William and Morris W. Travers. “On a New Constituent of Atmospheric Air” (9 June 1898). Proceedings of the Royal Society of London, 63, 1898, 405–08 at 407. JSTOR.
Photo credit: Heinrich Pniok, 2006. Wikimedia Commons. Used under a Creative Commons ‘Attribution-NonCommercial-NonDerivative 3.0 (US) license.