The underlying concepts between the Periodic Table of Elements are kind of bizarre from the outset. After all, adding or removing a single proton in an atom’s nucleus completely changes the nature of the substance, making it a different element with different properties. Thanks to our understanding of subatomic particles, and to the classifications that Mendeleev set out and that many others added to, modern science can more or less do what ancient alchemists sought to when they tried to transmute matter. That’s weird enough as it is, but when you consider some of the logic-defying abilities of certain elements, those same alchemists would stop calling it magic and start to believe they were going mad.
Once upon a time, it was thought that gallium (31Ga) was named for an atrocious pun–its discoverer was a French chemist named Paul Emile Lecoq, and “le coq” is French for “the rooster,” which is “gallus” in Latin–but Lecoq always maintained he called his discovery after his homeland, which the Romans called Gallia. Bad-Latin-joke controversy aside, gallium is a soft metal that doesn’t occur in pure form in nature but can readily be smelted from minerals. Aside from its useful properties in electronics, it does something that metals, according to our conventional understanding of them, should not do–it melts safely in a human hand, then resolidifies into brittle crystals once it cools down below its 85-Fahrenheit melting point. One gallium alloy with iridium and tin has a melting point 34 degrees Fahrenheit below the freezing point of water, meaning it’ll still flow freely outdoors on a negative-temperature winter day when everything else is ice. This became the basis for “hilarious” chemist pranks at universities at the beginning of the 20th century involving gallium utensils at meals.
The conventional wisdom about radioactive elements is that they undergo decay simply because they’re so heavy, with the intra-atomic bonds not able to support all of their protons, and that nuclei become more unstable the more massive they become. This holds up pretty well when you consider that polonium is atomic number 84 and uranium is 92, but then there’s technetium with its 43 protons, innocuous and inert molybdenum (42Mo) and ruthenium (44Ru) to either side of it… and zero stable isotopes. Yes, this random transition metal in the same-y midsection of the table is crazy radioactive in any form, just to shake things up. Thankfully it’s hard to just stumble upon this stuff in nature, and mostly it’s a spontaneous fission product from uranium.
Another element on this list named for France. What is up with the, uh, French connection and weird substances? Anyway, francium (87Fr) is a fairly heavy metal, so it being unstable is par for the course. But it’s hard to overstate just how volatile francium is. Not only is it as electronegative and as pyrophoric as cesium (55Cs), which explodes into an inferno with just a drop of water at up to -177 Fahrenheit, it also has a half-life of 22 minutes in its most stable isotope. Given an observable quantity of francium, and hopefully a sufficient distance from the whole exploding-from-moisture-in-the-air and colossal-amounts-of-radiation thing, you could just sit back and have a picnic while watching it annihilate itself before your eyes. Good luck getting one though–francium was the last element discovered in nature (Marguerite Perey in 1939) because it definitely does exist in the Earth’s crust; about 20 grams of it on the whole planet, anyway.
The soft, lustrous, and dare we say luscious (okay, no, it tastes pretty gross) metalloid antimony (51Sb) has that abbreviation because it was known to the ancient Romans, who called it stibium. Weirdly, everyone in the ancient world seemed to think it was a form of lead. When an element has been part of the corpus of human knowledge for that long, people start dreaming up some very, shall we say, interesting uses for it. The predynastic Egyptians used antimony sulfide as eye makeup, which at least sort of makes sense, but the Victorians were never ones to make the effort to be not-gross and came up with the antimony pill as a laxative which was meant to be retrieved from the other end and reused.
When discussing gallium we said that one thing a metal should not do is melt in a human hand and refreeze when a little colder. Well, what would make even less sense than that? How about a metal that’s a gas at room temperature? Well, copernicium (112Cn), the former ununbium, is one of those super-radioactive synthetic elements that scientists talk about and that get a footnote in chemistry classes. It’s definitely a metal, it definitely doesn’t last long, and it… probably is a gas at standard temperature and pressure. That’s right–given a sample of copernicium that wouldn’t decay almost instantaneously, you could literally breathe in metal. And since scientists can’t yet get copernicium to cooperate for long periods of study, we haven’t even scratched the surface of its high weirdness yet.