A black and white drawing of Tantalus, neck-deep in water, fruitlessly reaching.

73. Tantalum: Mystery Meat

Once more, the periodic table drags us to hell — this time by way of ancient Greece.

Featured above: Tantalus reaches fruitlessly.

Show Notes

horns.aiff: You might remember that there was significant confusion surrounding the discoveries of niobium and tantalum. For a while, people thought tantalum wasn’t a real element, that nonexistent elements were real, all sorts of nonsense. One such extraneous element was pelopium, proposed by Heinrich Rose in the 1840s. It would’ve been cool to get the mythological hat trick on the periodic table, but alas, what Rose called pelopium was just an odd sample of niobium.

There’s Always One: Not every resident of Mount Olympus sussed out Tantalus’ horrifying trick. Demeter was really distracted at the time, because the ink was still wet on her daughter’s missing persons report. So, absent-mindedly, she took one bite of that stew before catching up with everyone else. The bite she took happened to consist of Pelops’ shoulder, so when he was reassembled, Zeus had Hephaestus make him a prosthetic shoulder of ivory.

Rather Different Results: Most tellings of the tale of Atlas don’t actually end with him getting rescued by Heracles. Rather, Heracles promised that he’d take on the titan’s burden (the literal heavens), but then tricked Atlas into taking it back on after retrieving some legendary golden apples. Funnily enough, it was Prometheus who gave Heracles the idea for this trick.

Weird Al: Sisyphus didn’t get more than a passing mention in this episode, but that’s enough of an excuse for me to share a particular passage by Albert Camus. He was an author and philosopher who grappled with the absurdity of life; the powerlessness of individuals to forge their own destinies. Please pardon me for quoting at such great length, but in The Myth Of Sisyphus, he wrote:

If this myth is tragic, that is because its hero is conscious. Where would his torture be, indeed, if at every step the hope of succeeding upheld him? The workman of today works everyday in his life at the same tasks, and his fate is no less absurd. But it is tragic only at the rare moments when it becomes conscious. Sisyphus, proletarian of the gods, powerless and rebellious, knows the whole extent of his wretched condition: it is what he thinks of during his descent. The lucidity that was to constitute his torture at the same time crowns his victory. There is no fate that can not be surmounted by scorn.

If the descent is thus sometimes performed in sorrow, it can also take place in joy.


I leave Sisyphus at the foot of the mountain! One always finds one’s burden again. But Sisyphus teaches the higher fidelity that negates the gods and raises rocks. He too concludes that all is well. This universe henceforth without a master seems to him neither sterile nor futile. Each atom of that stone, each mineral flake of that night filled mountain, in itself forms a world. The struggle itself toward the heights is enough to fill a man’s heart. One must imagine Sisyphus happy.”

(Emphasis mine.)

Neither Precise Nor Accurate: Well, how embarrassing. It looks like my numbers were out of date, and the lower bound for tantalum-180m’s half-life is actually an entire order of magnitude higher than what I said in the episode (and then double that). The idea remains the same, but I aim to do better than that.

Everybody Needs A Little R&R: If you ever happen to find yourself at the HADES in Belgium rather than the one belonging to the dead, you could spend a day on the lovely little nine-hole golf course nearby, Golfclub Nuclea.

Episode Script

Anders Ekeberg discovered tantalum in 1802, and for the next two hundred years, the element saw widespread use as… nothing much. Even after Werner von Bolton successfully isolated the first pure sample in 1903, there weren’t really any reasons to use it. For one hot minute, it was used as a filament in light bulbs, but it was quickly supplanted in that role by tungsten.

But that kind of thing can change in an instant. By the 21st century, tantalum found use as a component of construction tools, high-end watches, and most importantly, electronics. Its performance in capacitors and resistors is unmatched. Countless modern electronic devices depend on tantalum’s electrical properties, including mobile phones and other computers. So tantalum has gone from one of the periodic table’s more obscure members to one that commands a steep price — in dollars, and in blood.

Tantalum is one of the many natural resources that Congo has in abundant supply. Congo is also the home to some of the most violent wars in modern history. (For more on that, listen to episode 60, neodymium.) Money made from tantalum extraction has directly funded those hostilities, including the Second Congo War and the Ituri Conflict.1 2

Obviously, these are factual historical and current events, tragedies of the modern era. But even down to its fictional namesake, tantalum carries a legacy that’s more gruesome and terrible than almost any other chemical element.

You’re listening to The Episodic Table Of Elements, and I’m T. R. Appleton. Each episode, we take a look at the fascinating true stories behind one element on the periodic table.

Today, we’re serving up tantalum.

We like to say that elements that share a group are related to each other, but tantalum and its upstairs neighbor, niobium, are more closely related than most. Specifically, like father and daughter. In ancient Greek mythology, Tantalus was a king and the father of Niobe, of the eponymous niobium, and Pelops, who has no association with a chemical element. Sorry, Pelops.

Tantalus was kind of a big deal. He was renowned far and wide for his great wealth, and regularly dined with the gods on Mount Olympus. Accounts vary, but it was at one of these divine banquets that he committed such an embarrassing faux pas. Some stories say that he tried to steal ambrosia and the nectar of the gods, other tales say that he merely stole the gods’ secrets. The third version, however, is significantly different.3

Rumor had it that the Olympians were omniscient — or at the very least, they could always tell what they were eating without being told. But Tantalus didn’t buy it. So, passing the psychopath test with flying colors, Tantalus murdered Pelops, chopped him up into little bits, and made a stew out of him. He sauntered up to the gods with the most innocent smile her could muster, but they already knew that something unthinkable was afoot.4 5

Presumably there was one long, very awkward beat before Zeus made two decrees: One, that this poor Pelops boy was to be put back together again and revived, and two, that this reprobate Tantalus would be given a punishment worthy of his crime. A tall order, to be sure, but if anyone could come up with appropriately creative castigation, it was the Olympians. These were the gods who sentenced Sisyphus to an eternity of boulder-rolling, who lashed Ixion to an endlessly whirling wheel of fire, and let’s not forget what happened to our old friend Prometheus.6

Tantalus was banished to the darkest depths of Hades, trapped neck-deep in a lake called Tartarus. (No relation.) Fruit trees of every variety spread their branches right over his head. When, in a state of deathless starvation, he reached for a pear or pomegranate or fig, the wind would always blow the fruit just out of his reach. Whenever he lowered his head, desperate to quench his endless thirst, the waters would recede from his chapped, cracked lips.

Perhaps Tantalus hoped that one day his torture might end. Some texts say that Heracles freed Atlas from his punishment, much like he did for Prometheus. Even Ixion got a moment’s rest when Orpheus played his lyre on a tour through the underworld. But no such relief was in store for the tormented king. Presumably he still goes without food or drink to this day. If anything, the false hope of rescue would make his suffering far worse than having certainty of imprisonment for all eternity. Like the fruits above and the water below, the possibility of freedom is ever out of reach, endlessly tantalizing.

Much like the mythical man who gives element 73 its name, tantalum itself can be found in HADES, deep in the underworld. Two hundred twenty-five meters deep, to be precise. In Belgium.7

HADES, you see, is the name of a laboratory about thirty miles outside of Antwerp. According to its website, it was “built in a deep clay formation for the purpose of researching the possibility of geological disposal in clay.” That’s just vague enough to make the facility sound far more boring than it actually is. The “geological disposal” they’re talking about is that of nuclear waste — although they emphasize that HADES is purely a research facility, and “will never be used as a final repository for nuclear waste.” Some things are so objectionable that they’re even unwanted in Hell, I suppose.

The research carried out there has been critical for the nuclear energy industry. For over thirty years, HADES has explored the feasibility of storing radioactive waste deep underground, especially within deposits of clay. That would be interesting enough on its own, but you can’t expect to build a sprawling underground nuclear laboratory without stumbling upon a few dark secrets of the universe.

One consequence of being so far beneath the surface of the Earth is that the laboratory is highly shielded from cosmic radiation — the background noise of the universe caused by the countless stars as they die and are born again. Almost all of those particles and rays get absorbed by the first few meters of soil, leaving a place like HADES practically silent, radioactively speaking. That makes it a prime location for studying nuclear phenomena that get drowned out by the constant cacophony of stars screaming across the universe. For every ten thousand cosmic rays that strike the Earth, only one will pierce that deeply.8

So in addition to nuclear waste, the scientists in HADES study the mysteries of dark matter, the origins of certain heavy elements, and more. Much of that work is done with the help of tantalum-180m.9 10

Last episode, we learned about nuclear isomers, because some people believe hafnium-178m can be weaponized. In stark contrast, tantalum-180m is the most stable stable isomer that can be found in nature. Theoretically it is radioactive, but its half-life is somewhere on the order of one quadrillion years. That’s around 73,000 times longer than the current age of the universe. No surprise, then, that no one has ever witnessed the radioactive decay of tantalum-180m. One way scientists search for answers to the aforementioned questions by bombarding the nucleus with various kinds of energy in an attempt to artificially induce that decay. So far, that’s never happened.11 12 13

Obviously, you don’t need to descend far below ground just to acquire a sample of tantalum.

One of element 73’s best features is that it’s extraordinarily hard, and can lend this hardness to other metals by way of alloying or plating. That’s not an everyday concern, but there are certain niche applications that really require the hardest stuff around. For instance, tool bits. When operating a machine that grinds against another surface at thousands of revolutions per minute, you want to make it out of something that can stand up to wear and tear. Tantalum carbide is just the thing, exhibiting hardness that’s on par with diamonds.14 15 16

Sometimes, tantalum protects something far more valuable: A brain. If someone who lands in the emergency room is missing a piece of their skull (say, thanks to an accident involving power tools), they may very well walk out of the hospital with a shiny plate of tantalum in its place. Just know that, unlike Mrs. Wrigley on The Adventures of Pete and Pete, the patient will not start picking up AM radio broadcasts.17 1819

When Anders Ekeberg discovered element 73, it made sense to give it a name related to Niobe. Niobium had only just been discovered the previous year, and as mentioned earlier, is directly above 73 on the periodic table. Ekeberg also thought it was an appropriate name because of “its incapacity, when immersed in acid, to absorb any and be saturated” — just like Tantalus himself could never absorb any water.20

Thankfully, tantalum is all around us. Now that you know the right places to look, there is no reason it should elude your grasp.

Thanks for listening to The Episodic Table of Elements. Music is by Kai Engel. To learn how Pelops almost did have an association with a chemical element, visit episodic table dot com slash T a.

Last time, I mistakenly said we’d be covering tungsten today. My apologies! Next time, we really will find out what’s up with W.

Until then, this is T. R. Appleton, reminding you not to invite Tantalus to your next pot luck.


  1. Mining Technology, On The Trail Of Tantalum: Tracking A Conflict Mineral. April 20, 2016.
  2. Investing News, Tantalum: Congo Conflict Metal. Melissa Pistilli, February 12, 2010.
  3. Olympian, Olympian 1, For Hieron Of Syracuse Single Horse Race 476 B.C. Pindar, via the Perseus Project.
  4. Ancient History Encyclopedia, Tantalus. Mark Cartwright, February 28, 2017.
  5. Encyclopedia Britannica, Tantalus. Last updated May 17, 2019.
  6. Ancient History Encyclopedia, Sisyphus. Mark Cartwright, December 14, 2016.
  7. SCK CEN, HADES Underground Laboratory.
  8. EU Science Hub, Underground Laboratory For Ultra-Low Level Gamma-Ray Spectrometry.
  9. EU Science Hub, HADES Produces Unexpected Spin-Off From Open-Access Measurement Into Realm Of Dark Matter. April 30, 2020.
  10. Physical Review, Underground Search For The Decay Of Tantalum-180m. Mikael Hult et. al., January 2006.
  11. EU Science Hub, Search For The Radioactivity Of 180mTa Using An Underground HPGe Sandwich Spectrometer. Mikael Hult et. al., 2009
  12. Applied Radiation And Isotopes, The Sandwich Spectrometer For Ultra Low-Level γ-ray Spectrometry. J.S. Elisabeth Wieslander et. al., May 2009.
  13. Physical Review Letters, Search For Dark Matter-Induced De-Excitation Of Ta-180m. Björn Lehnert et. al., May 7, 2020.
  14. Sources differ on whether it’s harder or softer than diamond.
  15. AZO Nano, Tantalum Carbide (TaC) Nanoparticles — Properties, Applications. May 30, 2013.
  16. Viper Carbide, Tantalum.
  17. Journal Of Neurosurgery, The Technique Of Tantalum Plating For Skull Defects. Lt. Col. Arthur J. Hemberger et. al., August 1944.
  18. AEM Metal, Tantalum Plate.
  19. Proceedings Of The Staff Meetings, Mayo Clinic, Cranioplasty With Tantalum Plate; A New Method Of Forming The Plate Prior To Operation. G S Baker, May 1, 1941.
  20. WordOrigins.org, Tantalum. October 29, 2009.

3 Replies to “73. Tantalum: Mystery Meat”

  1. Thanks TR for your latest. Hope you are settling into your new digs and wishing all the best with the family. Appreciate your efforts as usual. Hadrian. Melbourne

  2. This was nicely done. Thank you. I’d like to introduce a thought, though. Nature has provided a gap between Pt 190, whose half-life is 48 times the current age of the universe, and Gd 152, whose half-life is 8000 times the universe’s age. The former is radioactive, the latter is stable for all purposes except close study of nuclear structure, nuclear reactions, or the universe of A.D. 10^14. It can be said with confidence at this point that no nuclide exists which fits into the gap in stability between those two. Calling something “effectively stable” if its half-life exceeds that of Pt 190 is a technology-independent distinction between nuclides whose radioactivity is important and those whose radioactivity is not. Specifically, Ta 180m1 is the one and only known stable isomer.

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