Added 1 new A* page:It occurred to me the other day that there's one chemical element that shares a name with an important figure in A*, and that is element 34, selenium! Both A*'s character Selenis and the element selenium get their name from selene, the Greek word for "Moon" (and the Greek goddess of the Moon); selenium's name came about because one of its discoverers in 1817, Swedish chemist Jöns Jacob Berzelius (considered one of the four founders of modern chemistry!—and discoverer of three other elements, with yet two more discovered by students in his lab; on the other hand, for a while he denied that chlorine was an element : o; he also originated the term "polymer," among others), noticed it was similar to tellurium, whose name comes from tellus, the Latin word for "Earth."
Selenium is also similar to sulfur, occurs in coal, and "is produced as a byproduct in the refining" of metal sulfide ores. Selenium is relatively rare, and although it has some interesting properties—in the 1870s for instance it was noticed that selenium "transmits an electric current proportional to the amount of light falling on its surface," which means it can be used as a light sensor, and was used by Alexander Graham Bell in his photophone in 1880, receiving a speech-encoded beam of light—it has gradually been replaced in most industrial and electronic roles by less expensive elements. It is still used in alloys, flexible solar cells, DC surge protectors, and photographic print toner, among other things. It is even in some anti-dandruff shampoos: selenium sulfide kills a scalp fungus.
Selenium is also an important nutrient: it plays roles in several antioxidants, in thyroid function, and in several rare amino acids. You don't need much of it—just about 55 micrograms a day (a microgram being one one-thousandth of a milligram!), and you probably only have about 13-20 milligrams in your body, total. Natural sources of selenium in our food are nuts, cereals, and mushrooms, with Brazil nuts having the highest concentration! Taking too much selenium (400 micrograms per day or more), though, can lead to selenosis, characterized by garlic-smelling breath, and, as selenium concentration increases, basically everything else going wrong with your body until you die.
Speaking of selenium and smells, remember that it is chemically similar to sulfur, which is responsible for our sweat smelling—so be sure to catch the chemists of the University of Nottingham telling us in their edifying and informative episode Selenium - Periodic Table of Videos why it is said that "people get off the bus when selenium chemists get on."
So that's selenium for you! Rare, deadly, good for hair, potentially smelly.
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