Symbol: U (good, no-nonsense symbol, that)
Atomic number: 92
Overview: Is there an element with a worse reputation than Uranium? My, you'd think the stuff could irradiate you simply by saying its name. And as the substance at the heart of Little Boy, the nuclear weapon dropped on Hiroshima, it's going to take a helluva PR job to improve its standing. Still, it looks quite nice in its raw form. When viewed through safety glass, of course.
Discovered: A tricky one this since geologists have uncovered prehistoric instances of naturally occurring fission involving uranium. As far as the realms of chemistry are concerned, Germany's Martin Heinrich Klaproth is usually credited as having discovered uranium, a feat he achieved way back in 1789.
What it looks like: A silvery-white metal. Although, unlike other silvery-white metals, uranium is best handled from a great distance. With tongs.
What it does: Reacts with just about everything. Oxygen, hydrogen, helium - you name a non-metallic element and the chances are it gets on about as well with uranium as the Pope does with Ian Paisley.
What it's used for: Making high density penetrators, weapons that can pierce pretty much everything except substances that have been coated with uranium which is to say modern-day tank armour. Uranium is also Homer Simpson's preferred nuclear power source.
You might not know this but: In Australian Aboriginal culture, it's believed that things that are buried underground such as Uranium have been put out of reach for a bloody good reason. Needless to say, Uranium mining is one of many processes that Aborigines take a very dim view of, in part because it’s caused damage to centuries old cave art such as that depicted above.