Monday, August 19, 2013

Element of the Month: Technetium!

August's Element of the Month:
Technetium image by Maria Ontiveros
used with kind permission.
Technetium!

Tc
43

Atomic Mass: 98ish amu
Melting Point: 2157 °C
Boiling Point: 4265 °C

Technetium is often paired with February 2013 Element of the Month Promethium. They are the two radioactive Elements (#43 and #64) that are relatively much lighter than all of the other radioactive Elements (#84 and up). One of the most significant things they share in common because of their radioactivity is that there's very little of either one of them around.

Mind you, Technetium is not always wildly radioactive. There's an isotope with a half-life of a good 4.2 million years, which is an awfully long time in terms of your average human lifespan. But since we've got the age of the Earth pegged down at about four and a half billion years, that has given all of the Technetium that was on board by the end of Genesis 1:10 well over 1000 "generations," so to say, of opportunities to halve itself (by transmogrifying into Ruthenium or Molybdenum).  [[I think.  A well-known open-source online encyclopedia seems to contradict this figure, and I'm not sure why.  Inquiries are underway.  [[UPDATE: As of this writing, the well-known open-source online encyclopedia has been amended according to my reasoning.]] ]]

That means, if I'd handled the math right, that if the Earth had started out as a big (silvery-grey, metallic) ball of pure Technetium, we would confidently expect that there would be considerably less than one atom of Technetium still on the planet today. This is a sufficient explanation for why you can't think of a single Technetium mining district.

Before all of this was ironed out, though, the big hole in the 43rd slot on the periodic table was downright confusing. Lots of people thought they had found Element #43 and got as far as naming it, sending out announcements, and telling all their friends, before someone else gave them the galling news that they actually been studying a tainted sample of Iridium or Niobium or something, and that the tenure committee was going to have a special meeting to reconsider their case.

The Centerfold!

Supposedly a sample of Technetium.

Thus it is that Element 43 isn't named Polonium, Ilmenium, Pelopium, Davyum, Lucium, Nipponium, or Masurium. Instead, it's named "Technetium," which is more-or-less Greek for "artificial." It was discovered in 1936 by brainy Italian guys at the University of Polermo, working with materials that had been part of the cyclotron owned by the University of California Golden Bears.

Since then, tiny tiny tiny quantities of Technetium have been discovered in nature, where it can be produced by the decay of some uranium isotopes. And apparently it can be generated in red giant stars. Still, it's mostly artificial. It has some important applications in medical imaging, so the few atomic power plants and labs that are tooled up to extract it from their nuclear waste apparently have a pretty good racket going. I'm telling you, if you come up with a cheap way to generate Technetium-99m, the world will beat a path to your doorstep.

2 comments:

gl. said...

"That means, if I'd handled the math right, that if the Earth had started out as a big (silvery-grey, metallic) ball of pure Technetium, we would confidently expect that there would be considerably less than one atom of Technetium still on the planet today."

this is blowing my mind a little.

Michael5000 said...

I aim to please.