Element of the Month: Neptunium!

September's* Element of the Month:
Neptunium!
Np
93

Atomic Mass: 237.0482 amu
Melting Point: 637 °C
Boiling Point: 4000 °C

Neptunium, Element 93, is the first “transuranic” element, which just means that it is the next in line – in the sense of having one more neutron proton, which is pretty much where the elemental action is – after Uranium (Element 92). See how that works? So no doubt you are guessing based on recent experience that Neptunium is another of the fakey elements. But it’s not! Despite being transuranic, Neptunium is a totally sincere element.

Interestingly, though, clever humans with expensive equipment were able to synthesize fake Neptunium in 1940, a dozen years before it was isolated in natural ores in 1952. Apparently the hunt for Element 93 was thrown off because for a long time the Periodic Table didn’t take the actinides into account. At some point in our tour of the elements, I will probably learn what an actinide is and that last sentence will become more clear. For the time being let’s just understand that our Element of the Month proved a shy little substance, and was falsely discovered any number of times (including by Enrico Fermi, who was an awfully smart dude) before the University of California Golden Bears produced some by throwing neutrons at Uranium.

The Centerfold!

Six kilograms of Neptunium, apparently.

There is enough Neptunium around that, unlike recent Elements of the Month like Lawrencium and Einsteinium, it is actually possible to say what it looks like, to wit: it’s a silvery metal like everything else. Indeed, there is likely to be rather too much Neptunium around in the long game, as several of the other transuranic elements decay into Neptunium fairly rapidly, but Neptunium itself has a half-life (in its most common form) of 2.14 million years, which is a long time to have fissionable material lying about.

The main source of Neptunium is extraction from recovered nuclear waste, for instance at that massive nuclear cleanup/mining operation upriver from the City of Roses. The main uses of Neptunium are in specialized scientific equipment and as part of the recipe for an isotope of Plutonium that is used as a power source in spacecraft. There is apparently also research ongoing into how Neptunium could be used to produce a new type of “nuclear weapons,” which are bombs capable of destroying entire cities or, if used in a carefully coordinated fashion, entire civilizations or indeed all of human life. In theory, the threat such destructive potential being held by a limited number of key global powers could entirely eliminate the phenomenon of war!


* Neptunium apologizes for running late.