Californium - The MOST EXPENSIVE Metal on EARTH!

[00:00:02]Is it possible to buy uranium? Yes, as you can see from these shots, it's quite possible. And according to the readings of the dimeters, there is indeed metallic depleted uranium inside this ampule. By the way, it's not cheap. It's about $18 per g. And what about other radioactive metals? And which one of them could turn out to be the most expensive to acquire and at the same time not decay in a fraction of a second? Well, let's figure it out.

[00:00:38]If you take a close look at the periodic table of chemical elements, you'll see that the most affordable metals are mostly located at the top since they are the most abundant on our planet primarily because of their low atomic mass. Of course, there are some minor exceptions like lithium, burillium, and boron. But the overall trend remains the same. The lighter the element, the more abundant it is on Earth and accordingly the cheaper it is. A similar trend is observed in the universe. There are a great many light elements in the universe. So many in fact that the lightest ones namely hydrogen and helium make up 98% of all atoms in the universe. While only 2% of all other atoms are made up of heavier and more expensive elements. Metals, by the way, make up only 2/10en of a percent in space. And even then 90% of those are light metals like aluminum or magnesium.

[00:01:28]The rarest metals in the universe just as on earth are the platinum group metals especially roodium and reinium.

[00:01:35]This is all due to a rare nucleiosynthesis process in which the probability of forming these elements is extremely low.

[00:01:43]But still we mine minerals only from the thin solidified crust of our planet which is where humanity gets all possible chemical elements. With our current level of technology, mining any deeper is not yet possible. Well, unless we drill some kind of super tunnel like in the movie The Core. Therefore, if we look at the abundance of elements in the Earth's crust, we can already see some small differences compared to, for example, their abundance in space. For instance, there is very little hydrogen and helium on Earth, while boron and burillium are present in about the same amounts as zinc. Otherwise, the trend is somewhat similar to the cosmic abundance of elements. There are many light metals in the Earth's crust, but far fewer heavy ones. But unlike their cosmic abundance, golden platinum group metals are on average 150 times less abundant in the Earth's crust than they should be. This is all because these elements react with very little. And during the early stages of our planet's formation, they existed in the protolanetary cloud in a free state. Because of this, most of them fused with iron and nickel, which were simply abundant in space. And after our planet formed, they all sank together into the iron core and disappeared underground.

[00:02:55]This process was made more straightforward by the fact that valuable precious metals have a tendency to dissolve quite easily in molten iron.

[00:03:02]Even when considering that the melting points of some of these metals can be considerably higher than that of the iron itself. That is exactly the reason why in one of my previous videos where I made an alloy from almost all metals, I used iron as the base. Since many metals, especially platinum or renium, dissolve quite easily in it, behaving much like sugar in water. As a result, because of this affinity of precious metals to alloy with iron, most rare metals are now located in the center of our planet, and there's simply no way for us to extract them. But if you think about it, if all the precious metals had originally alloyed with the iron core, then the Earth's crust would have become almost sterile, and we simply wouldn't find any rare metals in it. But it's not that simple. While gold and other precious metals still remained within the solid rock in trace amounts, most of these valuable elements were brought to our world by intense meteorite bombardments, of which there were a vast number over the 4 billion years of our planet's long history. And since the concentration of gold and platinum group metals in meteorites is quite elevated, these precious elements gradually became integrated with the metals that were already found within the Earth's crust.

[00:04:12]Gold being the most inert metal is mainly found in its pure form while the other precious metals are obtained as byproducts for example from copper nickel ores since they have chemical properties similar to nickel. If we look at prices the most expensive of the platinum group metals right now is roodium which costs about €350 per gram.

[00:04:35]So what about even heavier metals? After all, in theory, there should be even less of them, and they should be more expensive. There's a small paradox here.

[00:04:44]If you look at the table of element abundance in the Earth's crust, and try to find the heaviest elements, namely the radioactive uranium and thorium, it turns out that there are several times more of them in the Earth than there are precious metals. And in terms of dispersion, they're similar to tin. But how is that possible? If we look at thorium separately, it is actually the most abundant radioactive metal on Earth. And that's not surprising since its half-life is as much as 14 billion years which is comparable to the age of our universe. Thorium in the universe is formed during the merger of neutron stars when atoms of other elements are bombarded with neutrons like from a machine gun. Because of this uranium and thorium are produced more quickly than for example roodium or gold. And since it has an incredibly long halflife, thorium in space can exist indefinitely for an almost infinite amount of time.

[00:05:37]gradually accumulating and mixing from different corners of the universe. Due to its large atomic nucleus, thorium hardly alloys with iron. So during the formation of our planet, it simply floated up from the iron core like a piece of wood, remaining mainly in the minerals of the Earth's crust, especially those containing rare earth metals. That is why near deposits rich in rare earth metals, you can often find high levels of radiation due to the naturally occurring thorium content in these rocks. As for the price, it is important to note that today there is practically no established commercial market for thorium, especially when compared to precious metals. Very few people are investing in thorium now and it has almost no practical applications.

[00:06:20]Yes, there are some developments regarding thorium reactors using molten salts, but so far things have not progressed beyond experimental prototypes and even in those thorium is used only in the form of compounds.

[00:06:32]That's why the price per gram of metallic thorium is currently set simply by the greed of the collectors who trade it. For example, a vial like this containing half a gram of metallic thorium can cost around €600.

[00:06:44]But here the price is more about exclusivity.

[00:06:47]On some websites you can find so-called scalar energy pendants. And if you try to perform a spectral analysis of such a pendant using a special dosimter with a cintilator, you can see on the graph that this pendant contains glass with thorium content, which by the way also glows under ultraviolet light. It turns out to be quite an unusual souvenir for radioactivity enthusiasts. In addition, thorium can be found in tungsten welding electrodes as well as in the electrodes of old Soviet xenon lamps. For example, like in the DKST 2000 lamp, which is hanging behind me.

[00:07:21]And yes, these electrodes also emit a slight background radiation due to the thorium content in them. And of course, there are also minerals containing thorium such as monazite and gadolinite which also emit elevated levels of radiation. Besides thorium, there is another common radioactive element on our planet, uranium. Unlike thorium, which easily mixed with ores containing rare earth elements and so to speak, spread itself thinly across the entire planet, uranium ore can only be found in strictly specific locations and often in concentrated form. Because uranium's half-life is three times shorter than that of thorium, there is also three times less uranium left on Earth. And uranium ore turns out to be about three times more radioactive than minerals containing thorium. Sometimes, by the way, you can come across very beautiful samples of uranium ore that even glow under ultraviolet light, like this piece of uranetite, which emits quite a strong radiation background. It's all because this mineral contains natural uranium, which consists of the isotopes uranium 238 and uranium 235.

[00:08:28]By the way, the half-life of the ladder is 10 times shorter than that of natural uranium. Metallic uranium itself is often sold in a depleted form that is as almost pure uranium 238 isotope which is not as radioactive as natural uranium.

[00:08:45]By the way, uranium is actually cheaper than thorium about $18 per gram which is why it also has more applications. Today depleted metallic uranium is used as the core of certain munitions due to its high density and even as armor for some tanks. In addition, because of its high density, it can be used as shielding against other more radioactive substances such as the isotope iridium 192 whose radioactivity is 27 billion times higher than that of uranium 238.

[00:09:17]And of course, we simply cannot forget the worldrenowned uranium glass in which this metal is carefully incorporated in the form of either dioxide or sodium uranate. To give the glass a distinct green tint, various ironbased compounds are also sprinkled into the batch for glass making, resulting in the so-called Vaseline uranium glass, which also emits a vibrant and beautiful green glow under ultraviolet light. Yes, uranium and thorium are certainly interesting, but they're not all that expensive if you compare their price to other metals like roodium or iridium. But what about radium, which 100 years ago was even more expensive than gold? Yes, about a hundred years ago, after Marie Curi and her husband Pierre discovered this new element, radium began to be used in medicine to treat cancerous tumors. All because of the incredible radioactivity of this element, which was about 300,000 times greater than that of uranium.

[00:10:09]Because of this, pure radium chloride powder can even glow with a bluish light in the dark, causing the so-called radioluminescence effect. About a 100 years ago, radiumbased preparations were used in the first radiation therapy devices which actually worked leading society to believe in the truly miraculous properties of radium.

[00:10:30]Supposedly, it could cure almost any disease. Unfortunately, at that time there was no oversight of medicines and the laws were very underdeveloped which many opportunists took advantage of trying to sell radium in any form attributing truly miraculous healing properties to such products. These included face creams, perfumes, and even radium suppositories. You can imagine what kind of not so beneficial effects they could have had. By the 1920s, due to such hype, the price of radium had risen to $120,000 per gram at that time, while gold a 100 years ago cost only 60 per gram. If you convert that to today's exchange rate, it turns out that a gram of radium in 1920 would cost about $2 million in today's equivalent. And this price wasn't even entirely speculative because to obtain just 1 g of radium, you had to process about 15 tons of uranium ore, which wasn't exactly cheap. The rarity of radium is due to the fact that it is a daughter product of the decay of uranium 238.

[00:11:34]But because of its short half-life, radium doesn't have time to accumulate in large quantities in uranium ore. So its concentration remains quite low.

[00:11:42]Roughly one part of radium per 3 million parts of uranium. Nowadays, radium is hardly used even in medicine since more effective and less dangerous radioarmaceuticals have appeared which are also cheaper to produce and safer to handle.

[00:11:56]But in fact, besides radium, there are even more radioactive elements in nature such as pollonium and astatine or for example francium.

[00:12:06]But nowadays, they are practically not used anywhere except for scientific research. But what about artificial elements that don't exist in nature at all? How expensive are they? If you look at the periodic table, you can see that after uranium, there are many other different metals. However, they have not been found on Earth. The reason is that unlike uranium, they have a much shorter half-life. And even if these specific elements were once formed in space, for example, during the violent merger of neutron stars, after several million years, they would have already completely decayed, which on the vast scale of the entire universe is actually a very short time. That's why to obtain elements heavier than uranium, scientists had to create special conditions and devices. And to see them, I am traveling 9,000 km from my home in California.

[00:13:18]And so I have arrived in the city of Berkeley which is located on the other side of the bay from San Francisco. Here not far from the Lawrence Hall of Science there is a cyclotron that is one of the first particle accelerators which was used to produce such heavy elements as neptunium and plutonium.

[00:13:36]This happened in 1940 at the radiation laboratory of the University of California as a result of the work of a group of scientists led by Glenn Seabborg. In their experiments, the scientists bombarded uranium foil with accelerated atoms of dutyium, the heavier isotope of hydrogen. As a result, atoms of plutonium 238 and neptunium 238 were produced, both of which were discovered in the same experiment. Interestingly, after this, all research on plutonium was classified and not even published until the end of World War II. This was because another isotope of plutonium, plutonium 239, had been discovered, which was capable of spontaneous fision and was very well suited for making nuclear weapons. After the discovery, plutonium began to be produced in nuclear reactors where uranium 238 was irradiated with neutrons to create this new chemical element. The weaponsgrade plutonium 239 that was obtained was used for the Manhattan project in which the United States aimed to be the first to create nuclear weapons, a goal they achieved on July 16th, 1945 with the test of the world's first atomic bomb, Trinity.

[00:14:48]Nevertheless, plutonium outwardly looks more like uranium or thorium, a shiny metal with a grayish coating of plutonium oxides. Its price is now difficult to determine, especially for weaponsgrade plutonium 239.

[00:15:01]However, its counterpart, plutonium 238, which already has civilian applications, is sold and even has a market price. For example, due to its ability to selfheat up to 600° as a result of radioactive decay, it is used in space thermmoelect electric power sources such as those in the Curiosity or Perseverance Mars rovers. The price per gram of this isotope is about $7,000.

[00:15:26]So generating electricity on Mars is not exactly cheap considering that the entire power unit of such a Mars rover costs about $80 million and contains 5 kg of plutonium 238.

[00:15:39]Well, now you know how plutonium is produced and why there simply isn't any on Earth. After all, its longest lived isotope, plutonium 244, has a half-life of only 80 million years, which is nothing compared to the age of our planet, 4 billion years. By the way, you can obtain an even more expensive metal from plutonium, which was also discovered in California. Well, here we are at last in California in the city of Berkeley where in the laboratory Berkeley Lab, which used to be called Lawrence Laboratory before it was apparently renamed, this is where the element California was discovered, named after this state. All of this happened in 1950 under the leadership of Glenn Seabborg and other scientists.

[00:16:22]Californium was discovered by bombarding curium atoms with alpha particles which were accelerated in a large 1 1/2 m cyclotron to 10% of the speed of light.

[00:16:32]The curium itself was also produced from the same plutonium using the same cyclotron. So in theory californium can be produced from plutonium in this device in a mere two-step process. But even so this method yields only a few hundred atoms of element number 98. But to produce a larger quantity of this element, it is better to use a special nuclear reactor that uses highlyenriched nuclear fuel consisting of almost 90% uranium 235.

[00:17:00]Essentially, weapons grade uranium is loaded into this reactor. In such reactors, the neutron flux is incredibly dense. So that for example, a piece of plutonium placed in the center is instantly bombarded by a huge number of neutrons almost as if it were next to a neutron star. Because of this, it begins to turn into curium and then into the extremely expensive Californium 252, the price of which is about $70 million per gram. And yes, such a high price is not arbitrary because even with a very dense neutron flux, the production of californium takes quite a long time. To produce just 1 g of this metal, plutonium must be irradiated with neutrons for an entire year. And plutonium itself is highly radioactive and decays over time. So here you constantly have to play a cat-and- mouse game with the laws of physics. And as if that weren't enough, the resulting californium is about 10 times more dangerous and radioactive than radium.

[00:17:54]This is all because in addition to emitting alpha beta particles and gamma radiation, the Californiaifornium atom can also spontaneously split in about 3% of cases, producing a rather significant neutron flux. And neutrons, let me tell you, are things you really don't want to mess with because if you get caught in their stream, you could end up becoming radioactive yourself. This is also called induced radioactivity. In addition, due to its high radioactivity, a gram of californium, if placed, for example, on a wooden table, will immediately begin to heat itself up and release about 2 kW of energy per gram as a result of radioactive decay. Because of this, it will most likely melt and later catch fire, illuminating everything around with a yellowish blue glow made up of a mix of thermal radiation and a radioluminescent cloud.

[00:18:42]After that, most likely the Californiaifornium will burn through the table and fall to the floor as a piece of glowing Californiaifornium oxide.

[00:18:49]Interestingly, californium is practically the last element that can be obtained in microscopic quantities. And for example, you can actually see at least half a gram of it in real life.

[00:18:59]Because of these unusual properties, californium is used today to start nuclear reactors since it is this metal that provides the initial neutron impulse to trigger the chain reaction in the nuclear fuel itself. And besides that, a few years ago, californium was used to produce the heaviest elements on Earth, for example, organin and flovium.

[00:19:17]They were produced by a radiating titanium foil coated with an ultra thin layer of californium which was then bombarded with atoms of calcium 48, another extremely expensive metal with a gram costing about 50,000. If we try to examine the physical properties of californium, they are similar to those of disproium, a rare earth metal that is located higher up in the periodic table.

[00:19:41]Although in theory californium should be a bit softer and also stick quite well to a strong magnet just like dprosium.

[00:19:48]But still due to its high chemical reactivity californium must be stored like europium in an inert atmosphere.

[00:19:55]However because of its high radioactivity you couldn't even hold it in your hands in a vial since even a minute would be enough to receive a lethal dose of radiation. But if we try to examine the chemical properties of californium, they should be similar to those of other actinides such as uranium or plutonium. For example, due to the large number of electrons in its atom, California compounds will still have a colored tint like plutonium solutions.

[00:20:20]Well, I think after watching this video, you've learned how heavy elements are produced and why californium is the most expensive metal on Earth. And if you enjoyed this video, as always, don't forget to give it a like and subscribe to the channel to learn even more new and interesting things.