Every element has a distinctive atomic number. The atomic number represents the number of protons in the nuclei. Isotopes have the same number of protons, meaning it’s the same element, but there’s a different number of neutrons. Carbon, for instance, has three isotopes – carbon-12, carbon-13 and carbon-14. Each one has six protons, but they have six, seven, and eight neutrons respectively. That’s pretty boring as far as isotopes go, and there are some that have some remarkable characteristics.
10. The Half Life of Tellurium-128 is Unbelievably Long
Tellurium can be found at 52 on the periodic table and is a silvery metalloid element. It’s also a little bit toxic, so try not to play with it. It has 8 isotopes and one of them, tellurium-128, actually earned itself a Guinness World Record thanks to the fact it has a staggeringly long half-life.
The number has been calculated at 2.2 x (10 to the power of 24) years. That’s an obscure number for most of us, so you can express it in another way, too. It’s 160 trillion times the age of the universe itself. The universe is nearly 14 billion years old as it is, so the half-life of tellurium-128 is about as close to forever as anything you’re likely to find in nature.
9. Astatine Isotopes Decay in the Blink of an Eye
On the opposite end of the spectrum from tellurium, astatine doesn’t have much of a half-life at all. Located at 85 on the periodic table, it’s also the rarest element on Earth, with only about 25 grams of it present on the planet at any given time. Why so rare? It’s those half lives again.
The longest lived isotope of astatine is astatine-210 with a half-life of 8.1 hours. There are 32 isotopes in total and none of them are stable. The shortest lived is astatine-213, which clocks in at a remarkable 125 nanoseconds. It’s also been said that astatine’s radioactivity is so powerful it actually destroys itself.
All the isotopes are radioactive and can be formed from bismuth in lab conditions. They’re sometimes used as radioactive tracers, but other than that, they don’t have a lot of uses in the world of science.
8. Gold has 41 Isotopes But Only One Is Stable
Gold is a very well known element and most of us would be happy to run across some of it out in the wild. It’s highly valuable and doesn’t corrode like many other metals. What is less well known is that there are actually 41 known isotopes of the metal. The one we know and covet is gold-197, and it’s the only stable isotope gold has. The other 40 are all radioactive.
Interestingly, gold-197 is observationally stable. That means that science says it should be radioactive but observation of it doesn’t follow through on that promise. So even though you’d expect it to be radioactive, it just isn’t. Overall, that’s been a good thing for almost every economy in history.
7. Germanium-72 Undergoes Unusual Phase Transition
Germanium is the 32nd element on the periodic table and it’s another metalloid, which straddles the line between metal and non-metal. It has five stable isotopes and Germanium-76 is the longest lived one, with a half-life of around 130 billion times the age of the universe. That’s not the most interesting of the isotopes, however. For Germanium, it’s isotope 72 that offers up a very unusual feature when it starts to warm up.
We understand certain things happen to atoms when heat is applied to a substance. As in the case of something like water, heat excites the atoms and makes them move more quickly. But what happens inside the atoms themselves? Germanium-72 proves it’s not as obvious as you might think.
There are 32 protons in germanium and, in germanium-72, 40 neutrons. Those protons form strong pairs that get weaker as the atom is warmed up. That makes sense with our water example. The problem is that, at some point, something unusual happens. When the temperature gets hot enough, the bond between proton pairs actually strengthens again. The reason for this is something called a phase transition. The stabilization occurs as transition begins before it weakens once more as the temperature continues to rise.
6. Iron-60 Was Found in Antarctic Snow
Everyone knows iron, one of the most common elements in the world, and so important they literally named an age after it. Without iron, all of our magnets would fall on the floor to say nothing of our inability to make pretty much everything we make out of metal in the world. It’s estimated there’s about 800 billion tons of crude iron ore containing 230 billion tons of iron in the world, so we have a lot to go around.
There are four stable isotopes of iron and 24 radioactive isotopes. One of those, iron-60 is the most stable with a half-life of around 2.6 million years. It’s also not the sort of thing that shows up just anywhere. If you want your own iron-60, you’ll need to go hunting for it because it’s born during stellar explosions, which is to say things like a supernova. When a star explodes, iron-60 is hurled out into the universe and small amounts of it will sometimes make their way to Earth. Some of it has even been discovered In the Antarctic snow. Out of 500 kilograms of pure snow that was collected to find samples, scientists found five iron-60 atoms. The first time the isotope was discovered on Earth was only 23 years in some deep-sea soil deposits.
5. Plutonium 244 Was Found on the Ocean Floor
Much like iron-60, plutonium-244 is not the sort of isotope that just shows up from nowhere. Unlike iron, there really aren’t any isotopes of plutonium you want to get too close to. There are 20 of them in total and they’re all radioactive, but the most stable is plutonium-244.
Traces of plutonium-244 were found on the bottom of the ocean in 2021 and it’s believed it went through a heck of a ride to get here. Plutonium-244 is made in some pretty intense circumstances. In this case, the plutonium was created when two stars collided and created a massive explosion. It likely also forms in supernovas alongside iron-60.
Plutonium-244 is not an isotope we can create easily on Earth at all. Different isotopes are made in nuclear reactors, but when plutonium-242 becomes 243, it only has a half-life of a few hours and can’t become 244. It’s been theorized that a nuclear weapon blast could potentially produce 244, but it remains only a theory and has not been observed.
4. Magnesium-18 Degrades Before It Forms
We’ve seen that astatine has a very short half life, but scientists have created an isotope of magnesium that’s so unstable they can barely observe it. Normally, magnesium has three stable isotopes and 19 unstable ones.
Of the unstable ones, magnesium-18 and magnesium-19 are particularly interesting insofar of their incredibly short lifespans. Magnesium-19 has a half-life of 5 picoseconds. That’s five trillionths of a second. If that seems like a short amount of time, which it is, then get ready for magnesium-18.
Magnesium-18 has not been adequately measured thanks to the fact it lasts for about a sextillionth of a second. It falls apart so quickly that electrons it can’t even pull electrons into order around itself to become an actual atom. It’s just a nucleus and then it falls apart. That means scientists can’t study it directly, rather they just observe what it did during the short time it existed.
3. There are Only 500g of Natural Promethium in the World
Promethium is an exceptionally rare element that has no stable isotopes, though it does have 38 unstable isotopes. It emits x-rays and is stunningly rare. Right now, on the entire planet, you’ll only find about one pound of naturally formed promethium in existence.That said, we can also make it in lab conditions by bombarding uranium-235 and neodymium-147 with neutrons.
In 1902, a Czech chemist named Bohuslav Braun theorized that promethium would exist along with six other undiscovered elements, and his hunch was confirmed some years later when Henry Moseley confirmed something had to exist on the periodic table between neodymium and samarium with the atomic weight of 61. It would be another 20 years of searching before it was determined that, whatever element 61 was, it wouldn’t have any stable isotopes.
After years of searching, promethium was finally discovered not in nature but in a lab when scientists realized that they could force elements and their isotopes into existence.
For something so rare and also radioactive, you might think it would have some kind of serious uses in the world at large, but you’d be wrong. Instead, it’s chiefly used for things like luminous paint and atomic batteries.
2. Strontium-90 is Processed in Your Body like Calcium
Strontium is an alkaline earth metal and occupies the 38th spot on the periodic table. It has 4 stable isotopes that occur naturally and also 32 unstable ones. Of those isotopes, strontium-90 is the one you need to keep your eye on because it’s a little sneaky.
Strontium-90 is very chemically reactive and can make heat. That reaction makes it useful as a power source and it’s used in remote weather stations and even space vehicles as well as in the medical industry. Though it’s not a stable isotope that occurs in nature, it is a by-product of nuclear fission, which is where most of the world’s supply comes from, though it was also produced as a result of nuclear weapons tests in the 1950s.
Because it’s radioactive, strontium-90 is obviously something you want to avoid, but it has an insidious way of making you sick when you get into contact with it. It can be inhaled, but it can also enter the body through ingestion of contaminated food and water. Once inside, your body will process it the same way it does calcium. That means the radioactive strontium will incorporate into things like your teeth and bones. Once it becomes a part of you, it can lead to bone cancer, marrow cancer, and soft tissue cancer of the areas around the radioactive portions.
1. Tritium is One of the Most Expensive Things On Earth
Hydrogen is the most abundant element in the universe and it has seven isotopes, though only three occur naturally. The last one, hydrogen-3, is the one we call tritium, and it’s as rare as it is valuable. It can form naturally in the atmosphere when cosmic rays hit nitrogen, but this produces only trace amounts. It’s also produced in nuclear explosions and as a by-product of nuclear reactors.
Tritium is used in the production of nuclear weapons, but also to produce things like luminous dials and for various scientific and research purposes. Pound for pound it’s one of the most valuable substances on the face of the earth as well. For instance, a gram of pure gold can be worth around $70, depending on a number of factors. A gram of platinum might be around $40. A gram of cocaine can be around $120, depending on where you buy it. But a gram of tritium? That’ll cost you about $25,000.
About four grams of tritium are used in a nuclear weapon to increase the efficiency and make the weapon more destructive while at the same time being lighter.