Are there any elements for which we have no use? Even the non-reactive noble gasses can be used in lighting elements.
According to Tim James in his book Elemental, dysprosium appears to be useless.
While you can use it for lots of things (eg lasers) apparently you can always find another element that does that thing better.
However Wikipedia does not entirely agree https://en.wikipedia.org/wiki/Dysprosium
About 100 tons are produced each year so some people want it.
There are plenty of unstable elements. What are you going to do with Fermium or Francium?
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I was always under the impression by itself Neptunium is useless but is used to make Plutonium, so it’s both incredibly useless but also incredibly useful.
Some unstable elements are used because of their radioactivity. Americium is used in smoke detectors and several (including californium and technetium) are used in nuclear medicine.
Sure, you say that now, but what are you going to do when you need to create the universe again?
There’s yttrium, ytterbium, praseodymium and promethium,
and niobium, iridium, mendelevium, einsteinium, nobelium,
There’s strontium and holmium and hafnium and erbium,
and francium and dysprosium and scandium and terbium,
These are the only ones of which the news has come to Dopers
And there may be many others but they haven’t been discovered.
(after Tom Lehrer)
Since the original rhymed “Hahvahd” with “discahvahd,” shouldn’t this rhyme “Dopers” with “discopered”?
Sure, you can use californium or something in nuclear medicine, but there’s no way you’re going to pull that off with copenicium or meitnerium. The only use for those is to honor someone you like with the name, or to show those damn <comunists/capitalists> who’s boss by beating them to synthesizing it.
I’m intrigued how many elements are essential for human life. For example, the human body contains only about 5 micrograms of molybdenum, and about 12 micrograms of manganese — tiny “trace” amounts, yet each is a key part of multiple human enzymes! Molybdenum, at about 1 ppm, is way down in the #54 slot of the crust’s most common elements, yet is an essential constituent of both the human enzyme xanthine oxidase and [sulfite oxidase](Sulfite oxidase), which is found in all mitochondria.
But Francium’s half-life is a mere 22 minutes.
There’s conceivably some weird use for it, I suppose, but it’s difficult to keep in stock.
And , although there are other lasers that can, I suppose, do what dysprosium does, dysprosium, like neodymium, is pretty efficient. And the new tunable dysprosium laser hits wavelengths that can be covered by color center lasers, but dysprosium is a LOT easier to handle and maintain.
I doubt if there is a “useless” element. Each element has unique properties. The Shakers believed (still believe, actually, although there are fewer of them now) that everything was created by God for a purpose, and went out of their way to find uses for even apparently “useless” plants. Shaker chemists and physicists would definitely look for uses even for Francium.
I’d argue that any named are just elements whose uses have yet to be discovered. Right?
I would have thought astatine as being basically useless and unusable, as its most stable isotope has a half life of eight hours and it is so radioactive that no one knows what a pure sample looks like, but research is being done on its medical uses
So maybe you are right
The larger elements require a ridiculous amount of energy to make and have millisecond half lives right? Other than the nobel for making it you can’t use a few atoms that won’t survive the time it takes to flush a toilet.
Today.
“What has Dysprosium ever done for us?”
“Magnets.”
“What?”
“Well, it’s made magnets more resistance to higher temperature.”
“Oh. Yeah, yeah. It does give us that. Uh, that’s true. Yeah.”
“Dosimeters for measuring ionizing radiation.”
“Oh, yeah, the dosimeters, Reg. Remember what the radiation lab used to be like?”
“Yeah. All right. I’ll grant you the magnets and the dosimeters are two things that Dysprosium has done.”
“And expansion resistant reactor core rods.”
"Well, yeah. Obviously the rods. I mean, the rods go without saying, don’t they? But apart from the magnets, the dosimeters, and the rods-- "
“Nanofibers.”
“Paramagnetic crystal salts.”
…
Dysprosii eunt domo!
I read somewhere that astatine is so radioactive that any amount large enough to see with the naked eye will vaporize itself. It is also insanely rare. I have heard that there is maybe 30 grams of it in the entire planet at any given time and only 0.05 micrograms (0.00000005 grams) has ever been produced in a lab by anyone.
So yeah…I’d say it is pretty useless since no one has used it for anything that I am aware of (except to study it).
See The Disappearing Spoon Flash Cards
Here is the listing for promethium:
-last element in periodic to be found
-element 61
-useless