Science Friday - SciFri Extra: Celebrating The Elements

Episode Date: March 12, 2019

Do you have a favorite chemical element? Neurologist Oliver Sacks did—he was partial to dense, high melting-point metals, especially those metals between hafnium and platinum on the periodic table. This month marks the 150th anniversary of chemist Dmitri Mendeleev’s design for the periodic table—and we didn’t want to miss out on the party. In this special podcast, we revisit Sacks’ fascination with the elements, and Ira opens up the Science Friday vaults to share two tales of chemical discovery and creation. First, we take a trip back to 2004 for a chat with nuclear chemist Joshua Patin of a scientific team responsible for the creation of two new chemical elements (elements 113 and 115). Then, a voyage to 2010, for a conversation with the late Nobel laureate and buckyball co-discoverer Sir Harry Kroto. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

This is Science Friday. I'm Ira Flato. This month marks a big anniversary for chemistry, 150 years since Dmitri Mendelayev proposed the design of the periodic table. He'll probably be seeing all sorts of chemical celebrations this month and this year, and we didn't want to miss the party. Mendelaev's table has influenced people far beyond those high school chemistry textbooks. For instance, when we spoke with neurologist Oliver Sacks over the years, Would you have guessed that he'd have favorite metals? Well, I think this partly goes back to my uncle tungsten,

my uncle who made filaments from tungsten and himself loved the density of tungsten and its refractoryness. And like him, my favorite metals are all very dense and have a very high melting point. And they're also very noble. They're not attacked by acids or alkalis. and I dream about them quite a lot.

My favorite metals come between 72 and 78, between Haphnium and Platinum. In this podcast extra, we're opening up the Science Friday vaults to bring you two tales from the periodic table. First, a story of element creation. We take you back to 2004, and the conversation with Joshua Patton, a nuclear chemist at Lawrence Livermore National Laboratory. Patton and colleagues had just published a report describing how a collaboration of scientists in the U.S. and Russia had created two never-before-seen elements, elements 113 and 115. The periodic table of the elements is that chart that's hanging in your classroom.

Of course, you've got one with you right now. Pull it out. Take a look at that periodic table. Of course, you carry one with you all the time, don't you? If you look at it carefully, you'll notice the gaps. There are spaces. spaces in the table left there for elements that have not yet been discovered or created. But now a team of scientists from Russia and California announced this week that it's done just that,

adding elements 113 and 115 to the periodic table. Their research is published in the current issue of the Journal Physical Review, and they did it how by smashing a high-energy beam of calcium ions into a target made of the element meresium. That's inside a giant particle accelerator. And the lead American author is here to talk about it. Joshua Patton is a nuclear chemist at the Lawrence Livermore National Lab in Livermore, California. He joins us today from his office. Welcome to the program. Good morning. Everybody's got their periodic table out now, I'm sure. Where do your elements fit in? We're situated in the bottom right-hand corner, sort of. And yeah, we're reaching there the edge of the highest ones that we've found so far.

And the nature only goes up to what, number 92, which is... Exactly. There have been some remnants of some... Uranium? Heavy isotopes of plutonium, also found in nature, but for the most part, uranium is the heaviest one found in nature. And these elements that you created don't exist in nature. No, they do not. Why do I keep seeing news reports that say that you discovered them instead of creating them?

I mean, if they existed in nature, you'd say you discovered them. Combination of both, I think discovery in the sense that they... never been seen before. It's something that was predicted to be there. And their theories that say that some of these heavy elements should be there and we should be able to see them with a sufficient enough half-life so that they're long enough that we could see them. And we've finally found them. So in that sense of, you know, we've discovered them in addition to having created them. Tell us, why do you want to fill in these teeth, his missing teeth in the chart? There's, I'd have to say there's two reasons. First, because there, as you mentioned in the opener, there's holes there.

There have been theories that said there could be there, so let's see if we can fill in those gaps. And I think of the second reason would be because, again, there are theories that say we're reaching an area where there's enhanced stability with these isotopes of these new elements. And when I say that, I mean that we could find isotopes of these elements with very long half-lives. sufficient enough maybe that if you created enough of these atoms, you know, they'd live a long enough time, you might actually be able to see some of it. So it's an interesting area of the periodic table as well as the chart of the nuclei where, you know, there's this increased enhanced stability. And our research, by finding them, is helping prove these theories, correct. How long did these new elements live for?

The element 115 lasted for less than 100 milliseconds, and that decayed to element. and 113, which lasted for around a second. A whole second? Yeah. That's a pretty long time in this business, is it not? It is a significant amount of time for the area that we're looking into right now, yeah. And that's what leads you to believe that there might be this island there that you call stability where other elements might exist?

True. It's where other isotopes of these elements might have even more stability, even longer half-lifes. If we could increase the number of neutrons, we could put into these reactions or in these elements that we would maybe see an enhanced stability in longer lifetimes. Tell us about how you made them. How do you go about using an atom smasher, as they used to call them, or now a particle accelerator to create these? You start first with the material.

We start with the projectile, which is the calcium 48, which is a highly enriched or has a lot of neutrons in the calcium. It's one of the largest calcium isotopes found in nature. Extremely expensive. You have to purify it. make sure that it's only just the calcium 48. Then you have the target material, which we had here at Lawrence Livermore National Lab, which was amaracium 243, a particular isotope of amarycium,

which was cleaned again and purified to make sure that decay products and such were taken out. And then we sent the target matron, which is what, as you mentioned, it's a particle accelerator. So they heat up the calcium 48. It gets injected into the cyclotron, which speeds it up and get it going to really high velocities. And then you use magnets and direct it at the amarycium target. So who gets credit? Both teams here? Yeah, it's a collaboration together.

They have the device, and we supply our expertise in terms of the chemistry involved in the purification of the targets, as well as in the data analysis side. This island of stability that you talk about, what direction, could you map out a direction it might go on the periodic table, or is it just the isotopes that you're talking about? It's just the isotopes that I'm talking about. Each of these elements that we've created has the potential to have more isotopes that we haven't seen yet. So in a sense, we could say, if you want to talk about the periodic table that we might find long-lived isotopes of element 114, 115, 116, that's what theory is said. And by doing the experiments we've done, we've kind of gotten an idea that they might be there, but there'd be longer-lived isotopes that we haven't seen of those elements.

Justin and South Bend, hi, Justin. Hi. Hi. Go ahead. Okay, I had a question. Do we have any new applications we can use for this to discover the elements? Currently, no. In the future we might, but right now there really is no practical application,

first because they just don't live long enough. And second, we only saw four of these atoms in the course of a month-long experiment running 24 hours a day. So it becomes very difficult to do anything, you know, to even investigate what kind of practical applications they might. have. So it's a stepwise process. First we discover them. First we see them. And next, we try to figure out a way to create more of them so then we can study the chemistry and just see if they actually fit on the periodic table where they should. And then if you can create even more of them,

we start looking at developing practical applications. So you only saw four atoms that came out of this? How many particles were bombarded or missed each other or what to get those four? It was, I think we sent on the order of one million, million, million calcium 48 ions at the target. So 10 to the 18th about, and we only saw four atoms of element 115. And why is that? It's very difficult when you get to this point of pushing two things with the positive charge that they have, like the calcium 48 nucleus, which has 20 protons, as well as the amorycium 243, which has 90. 35 protons, to put that much positive charge together, it takes a significant amount of energy.

And even in that, it doesn't happen too often. Another thing you're fighting is even if you do get the two to fuse together, the majority of the time that new 115, if that's in fact what it's created, falls apart. There's so much energy inside that when the fusion process takes place, that it decides just to fission, and it just separates into two smaller nuclei. instead of staying together as the 115. So there's that small probability of it actually surviving the process. So you put those factors together, and it becomes a really rare process.

But I guess in quantum physics, a small probability can happen. Yes. So if you do it enough. You do it enough for those collisions to happen, something, you'll get four of them out of millions, of millions of millions of them. Yes. And is there a reason why they stay together and don't split apart as quickly, or is it just a matter of chance? It's just a matter of chance in the probabilities that are involved.

Ben in San Francisco. Hi, Ben. Yes, I was wondering, how large are the projectiles and the target itself? I mean, you said there are hundreds of millions of how big physically, I mean, could we see it? And how far would you be throwing, were you sending them? How long are the distance that you're shooting them? The distance isn't that far. This, I think, is probably only a couple or tens of meters.

Size-wise, though, if you had a million, million, million of these calcium 48 ions together, if they were just in the atoms, that would be on the order of a couple of micrograms, I want to say. It's a very small quantity. It's still a small quantity, and it'd be very difficult. You might be able to see a little bit of it. We use milligrams of calcium 48 during the experiment, and we're efficient enough to get about, you know, 10 to the 18th of these to actually go down this beam pipe to hit the target. Now, in terms of the amoreseum, again, it's a milligram's quantity of

amarycium 243 that will be played onto this target. So the target size is actually maybe the size of a, it's in the shape of a disc. So I think one of the things we used to describe it as would be one of the old floppy disks. It's a large size floppy disk, one of the old, I think, an eight-inch size, actually even larger than that. The old old old old. The old one. Yeah. But that's the size of the target wheel, and the target is around the outside of that. You're dating yourself now, you know, talking about those old floppy. Yeah. All right, thank you.

Thanks, Ben. And you've named these sort of unusual names so far. Well, we haven't given them many names. The International Union of Pure and Applied Chemistry is the one that decides on the names, and they have a method to name elements that are recently discovered. So that's why they give them the initials U-U-T and U-U-P. if the experiment is ever done again, exactly what we've seen and confirms what we've seen,

then our group, our collaboration, we'll get together and propose a name to this IU PAC, as it's called, this International Union of Curi and Applied Chemistry, and then they'll decide. So it's not going to be a patinium or something? No, no. We don't even think about names.

It's a process that needs to take a while. Seaborgan was discovered in 1971, I believe, and it took, you know, 26 years or 36 years before it was named. It didn't get its 26 years. It didn't get its name until 1997. So it's a process that's going to take some time. Are you now, I've got about 30 seconds left.

Are you now tweaking it up, going for something else? We have been working on other experiments. In the past, we've done experiments on Element 114 and Element 116. We continue to do experiments with those, just trying to increase the number of atoms that we see. In the future, we'll probably be shooting for Element 117 and 118. Well, happy hunting, and we'll have you back. Thank you very much.

That was Joshua Patton, a nuclear chemist at Lawrence Livermore National Laboratory. Element 115 was not officially recognized until 2015, and in 2016, it was officially named Moscovium, symbol MC, after the site in Russia where the accelerator work was done. Element 113 was also confirmed. But as a team from Japan's Research Institute, Reichen, turned out to have observed it slightly before the Russian Livermore Collaboration, Dr. Patton was part of, that element received the name Nehonium, symbol N-H, in a nod to the Japanese language name of Japan. The periodic table is currently up to element 118. Of course, it's never complete because it always contains that numberless element of surprise. Of course, it's not enough

just to know about an element. You need to be able to do something with it. In 2010, I spoke with the late Harry Croto, who shared the 1996 Nobel Prize in Chemistry with Robert Curl and Richard Smalley for the discovery of Bucky Balls, Fullerines, those soccer balls made of carbon atoms. When we spoke, it was coming up on the 25th anniversary of that discovery. 25 years ago this month, 1985, a series of experiments identified a new form of carbon structured not like a flat sheet, like your graphite in your pencil, or a crystalline structure like that diamond on your ring, but pure carbon

in a previously unidentified structure shaped like a soccer ball. Joining me now with Sir Harry Croto. He's founder of Global Educational Outreach for Science Engineering and Technology and the Vegas Science Trust. He shared the 1996 Nobel Prize in Chemistry for the discovery of fluorines.

Spucky balls, as they're called. He's Professor of Chemistry at Florida State University in Tallahassee. Welcome back to Science Friday, Dr. Krodo. It's pleasure to be here, as usual. Thank you. 25 years? Have you had a party, a reunion? Anything like that? We're going to have a party in Houston next month. There's a big sort of celebration and conference and meetings and probably some good food. You never know.

It may be lucky. I'm looking for my invitation. Well, I'm sure it can be arranged. Let me put that down on the list. Take us back those decades. What were you actually looking for that you came up with the Bucket? Well, it's one of those wonderful serendipities. or blue skies research, or in this case, black skies research, about the 1970s, we had detected some carbon chain molecules, very long carbon chain molecules by radio astronomy, and then the development of infrared indicated there were some very interesting stars, and then a little bit later

these molecules were coming out. They're long carbon chains, just linear chains of carbon atoms. And as luck would have it, I met Rick Smalley at Rice University. through my friend, Bob Curl. And as Rick was jumping over the apparatus and excited about the breakthrough that he'd made, vaporizing metals and silicon, I thought, well, maybe you could vaporize graphite and simulate the conditions in a red giant star and see these carbon chains. It's a very simple idea.

And we did that a year later with students, Jim Heath and Sean O'Brien and Yu-An-Lew. and this crazy molecule just came out of the blue and said, you know, look, forget those linear stuff. I'm the biggest guy on the block. A very strong signal of 60 carbon atoms hit us in the face and just you couldn't miss it. It just was up there. Everything else paled into insignificance. And then on the basis of ideas from Buckminster Fuller's geodesic domes and one of two other ideas,

we concluded that maybe it was a geodesic dome, the shape of the soccer ball. And when we came to the right of the paper, I suggested we call it after Buckminster Fuller, and call it Buckminster Fuller. And then later, kids just love Bucky Balls and stuff like that, so it's been a great sort of serendipitous breakthrough. And in the meantime, you've discovered you could engineer all kinds of things out of these Buckeye Ball. Oh, there are something like 20,000 papers now on the chemistry of it, But also, the breakthrough in making it, which was about five years later,

it's the 20th anniversary of that, by an American German team, Kretchenman and Huffman, they found a very efficient way of making it. It then became a big chemical sort of research program. Everybody could work on it. But it also led to the discovery of the nanotubes or the Bucky Chubes, and this has sprung off as a major area of nanotechnology, research and very exciting because these nanotubes solve a lot of interesting problems. And promise, I would say, the strongest material that could ever be made.

But before we get there, there will be some major technical issues to be solved in engineering, chemical engineering at the synthetic level to be solved. I remember early on when we talked about this because the Bucky Balls were hollow. I talked about filling it up with stuff and engineering it that way. And that's an interesting point because you can put an atom on the inside. In fact, the very first experiment after we concluded or conjectured that it was a cage was, well, how do you prove it? Well, if it's a cage, well, you know what you do with a cage.

You put things inside. Well, it's too small to put a parrot in there. So the obvious thing is put an atom in the inside. And I suggested iron. Let's put iron on the inside of it. But that didn't work. But Jim Heath found that he could put Lanthanum inside, and that was the second paper that we could put an atom on the inside.

And that was very important to circumstantial evidence that our idea that it was a cage was actually correct. We've heard of all kinds of new things and made out of carbon, different kinds of carbon. What is this thing called graphene? Well, graphene is very interesting. It's a single sheet of graphite. Graphite is actually a sandwich structure.

So when you have a pencil, if you actually, what you're doing is you'd write, you're shaving graphite onto the pencil. paper. Now, these sheets are sort of flow off the pencil. But if you take a single layer off the top, you have a very interesting material, which is now the subject of a lot of study, have some very interesting electrical and electronic properties. And it's opened up a new field of carbon chemistry. So it's not that the graphene wasn't known before. It's just that nobody had thought of trying to take a single sheet of these. And the single sheet has,

interesting properties that differ considerably from a bulk system in which you've got hundreds of sheets stuck together. And now, I've heard it said probably by you that Bucky Balls are the most pure form of carbon, even though we've heard of other carbons like, you know, that's in a diamond ring and stuff. Well, yes, you see, the problem with diamond is that on the surface there are carbon atoms, and if the surface carbon atoms are what we call dangling bonds, and they're very reactive. So the surface of diamond is not carbon in general, it's hydrogen and oxygen and whatever comes out of the atmosphere, water vapor. But if you put the diamond in a very high vacuum and clean the surface, then you get a very unusual sort of surface which you don't know almost.

So diamond can never be actually pure because there must be something, a very thin layer of just single atoms on the surface so you don't notice it because they're pretty small. And the same is true. graphite. On the edges of graphite, you have what are called dangling bonds. So in graphite, you have hydrogen or hydroxyl groups. So that's not pure as well. Now, in the case of C60, however, the beautiful guy, it's curved into a ball. And so it gets rid of its edges by curving into a round structure. And it's a little bit, there's a little bit of a comparison with water. When you have a large amount of water, it's flat, pulled down by gravity. But if you have a small droplet, it curves into a ball by surface tension, right?

If you've dropped it on a leaf, you've seen those photographs, and everybody's seen those beautiful photographs of insects on leaves and water droplets. At a very small scale, the structure is controlled by surface tension, and that's the case in nanotechnology that in the case of very small numbers of atoms, they're controlled often by different forces than is the case when you have a large number of millions of millions of atoms. What is there about the shape of Bucky Bowles, a C-60, that makes them so amenable to use them in chemical engineering ways? Well, there are interesting aspects.

I mean, the first one that I most interest me, and I think is probably the one that will in the future be important, is that because it's a round object, it can trap electrons on the surface, and so it can store electrons better than almost any other. molecule. And that's very useful in things like solar energy production and in organic solar cells. I think Alan Hager at Santa Barbara, also a Nobel Prize winner for his work on organic sort of conduction, has been developing materials which could be printed onto, say, plastic as a solar cell by printing press technology. This is very exciting. And what you need are molecules which very have some very important

characteristics. One is to capture electrons and not let them go. And that's what C-60 can do. The other interesting thing, of course, is you can put something on the inside of it, and it's physically trapped, rather than chemically trapped. Now, this is really interesting because

say you're thinking about chemotherapy and very many of the radioactive elements that are used in chemotherapy and radiation therapy are actually toxic, right? So if you put it in C60, it should be possible to tag the outside of the C60, trap the radioactive toxic atom on the inside, and use it, put it close to, say, the cancer tissue, but it won't have its toxic

problems that one has in chemotherapy. The big problem in chemotherapy is, as those who've had it, will realize it's not the radiation, but often it's the toxicity of the agent that's being used. Now, that's because it's chemically bonded. It won't leak out of a bucket ball. No, it can't get out of the bucky ball. And that's, it's physically caged in a different way from standard chemical problems. And that's an interesting aspect that people are trying to look at.

And also with, say, agents in MRI, what I call a relaxing agent that relax the spins in MRI. It should be possible to make them non-toxic by putting them inside the bucky ball. theoretically, anyway. But it's tricky stuff. You're at a man to do it, I think. Well, not really, because I'm, you know, we discovered it because we were working in a particular area. I'm not really working on that. I work on things that interest me, and now what interests me is the fantastic results are about six weeks ago from NASA, the detection of C-60 in space,

because when we discovered it, we found it in, on the conditions produced in carbon stars. We reproduced the conditions in the carbon star in the laboratory. And at that point, it was telling us that maybe this stuff was coming out of the stars as well. And in 1995 with Mike Jure at UCLA, we published a paper suggesting that if it was in space, it should be responsible for some very puzzling features that have been known for 90 years, called the diffuse interstellar bands. And I think now that it's been detecting in space, that that particular paper looks really rather interesting. It now looks, I mean, I've just been talking to Mike in,

California by email, and the estimates are that 1% of the carbon in the interstellar medium may be in the form of C-60. And that's fantastic because it's the third form of carbon, and it reminds me of the third man, you know, Austin Wells in the third man. So here's this guy lurking in the shadows of Vienna, and here's this molecule lurking in the dark recesses of the gallery. And it's been there all the time. And, Ira, you have made it, believe it or not. I have made it. Yes, you have. because every time you turn a Bunsen burner to yellow, you make C-60.

There you go. There's the project for the weekend. Yeah, but you have to suck it out of the center of the flame, because as it goes through the flame barrier, it's lost again. Don't try this at home. No. All right, Harry, thanks for you. Stay off those ferris wheels.

Yep, see you soon. Bye. Bye, by Sir, Harry Crotto, who won the Nobel Prize, a 1996 Nobel Prize for the discovery of Bucky Balls, and he's Professor of Chemistry at Florida State University. Dr. Croto was known for co-discovery of Buckminster Fullerines, of course, but turned in later years to working on ways to improve early science education. Sir Harry Croto died in 2016 at the age of 76. We hope you enjoyed our little trip into the Science Friday Archives.

And we wish you the very best in your own celebrations of the periodic table all throughout 2019. See you on Friday. I'm Ira Flato in New York.