How much iridium is there on earth

Heat of fusion. Heat of vaporization. Vapor pressure P Pa. Crystal structure. Oxidation states. Ionization energies. Atomic radius.

Covalent radius. Magnetic ordering. Electrical resistivity. Thermal conductivity. Thermal expansion. Speed of sound thin rod. Young's modulus. Shear modulus. Bulk modulus. Poisson ratio. Mohs hardness. Vickers hardness. Brinell hardness. CAS registry number. Ir is stable with neutrons. Relative supply risk 7. Young's modulus A measure of the stiffness of a substance.

Shear modulus A measure of how difficult it is to deform a material. Bulk modulus A measure of how difficult it is to compress a substance. Vapour pressure A measure of the propensity of a substance to evaporate. Pressure and temperature data — advanced. Listen to Iridium Podcast Transcript :. You're listening to Chemistry in its element brought to you by Chemistry World , the magazine of the Royal Society of Chemistry. This week a rare, sexy, superhero of an element whose name is a little bit deceiving.

Here's Brian Clegg. There are many reasons to single out an element - in the case of iridium it has to be because it has the sexiest name. It's the sort of name a science fiction writer would give to a new substance that was strong yet beautiful. It's a name that belongs to a superhero of the elements. So how does the real thing live up to the name? It's hard, certainly, a dense silver-white transition metal of the platinum group, looking a bit like polished steel, but not quite as flashy as the name sounds.

It's not iridescent itself. Yet its name derives from the same source. When Smithson Tennant, later professor of chemistry at Cambridge, gave it the name in , he was referring to Iris, the Greek rainbow goddess.

He said 'I should incline to call this metal iridium, from the striking variety of colours which it gives, while dissolving in marine acid. Iridium was originally found as a contaminant with the element osmium in platinum, and it was from the solid remnants left when platinum was dissolved in a mix of sulphuric and hydrochloric acids that Tennant made his discovery of both elements.

He might equally well have named iridium after its weight - it's more than twice as dense as lead, and with osmium it's one of the two densest of all the elements there is some dispute over which is the heaviest, though osmium usually gets the laurels. Alternatively, Tennant could have reflected on its extremely high melting point, of nearly 2, degrees Celsius. That 'superhero' feel also comes through in iridium's resistance to corrosion.

We're used to gold and platinum as the exemplars of metals that stay pure, but iridium fights off corrosion better than either. It was partly for this reason - and the metal's sheer hardness - that iridium was first put to use in alloys to make the tips of fountain pens. Set in gold, these nibs shook off the worst ink and pressure could put on them. To this day you will see fountain pens claiming to have iridium nibs, though in practice it has been replaced by cheaper materials like tungsten.

There was only ever a small percentage of iridium in these pens, which is just as well. It's a rare material that makes platinum seem commonplace. There are only about 3 tonnes of iridium produced each year. These days it is more likely to turn up in the central electrode of spark plugs, where its resistance to corrosion and hardness are equally valuable. You'll also find it in specialist parts of industrial machinery.

Iridium, with atomic number 77 and two stable isotopes, and , turns up in an alloy with platinum in the standard bar and weight used for many years to define the metre and the kilogramme. Now, though, the distance is defined from the speed of light, permanently fixed in as ,, metres per second. As the second is accurately defined by an atomic clock, the metre falls out of the calculation.

Iridium has also found its way into space, both as a secure container for the plutonium fuel of the nuclear electric generators on long range probes and as a coating on the X-ray mirrors of telescopes like the Chandra X-ray Observatory.

But perhaps iridium's best-known claim to fame is as a clue in a piece of 65 million-year-old Crime Scene Investigation. The concentration of iridium in meteorites is considerably higher than in rocks on the Earth, as most of the Earth's iridium is in the molten core. One class of meteorite, called chondritic meaning they have a granular structure still has the original levels of iridium that were present when the solar system was formed.

This layer contains considerably more iridium that would normally be expected, suggesting that there may have been a large meteor or asteroid strike on the Earth at this time. There is so much iridium present that the asteroid would have to have been around 10 kilometres across - sizeable enough to devastate global weather patterns, bringing about changes in climate that could have wiped out the dinosaurs.

It was iridium that provides the principle clue as to why we now believe that so many species were wiped out, leaving the way clear for mammals to take the fore. In one small way, iridium disappoints.

Unlike its oxides, the element itself doesn't display the rainbow hues that its name suggests. But that apart, this is a true superhero of an element: tough, practically incorruptible and, yes, extremely dense. So, a rare metal that not only has uses varying from fountain pens to telescopes but also helped us understand the extinction of the dinosaurs. Now next week a colourful element that likes to shed a tear.

Indium is a soft, malleable metal with a brilliant lustre. The name indium originates from the indigo blue it shows in a spectroscope. Indium has a low melting point for metals and above its melting point it ignites burning with a violet flame. Bizarrely, the pure metal of indium is described as giving a high-pitched "cry" when bent.

This is similar to the sound made by tin or the "tin cry", however, neither of them is really much like a cry! And join UCL's Claire Carmalt to find out what tricks, other than crying, indium has up its sleeve in next week's Chemistry in its element. Until then I'm Meera Senthilingam from the nakedscientists. Chemistry in its element is brought to you by the Royal Society of Chemistry and produced by thenakedscientists.

There's more information and other episodes of Chemistry in its element on our website at chemistryworld. Click here to view videos about Iridium. View videos about. Help Text. Learn Chemistry : Your single route to hundreds of free-to-access chemistry teaching resources. After this treatment, the residue separated into two new elements. At the Royal Institution in London he announced his findings and named one element iridium and the other osmium. The name iridium comes from the Latin word iris, which means rainbow.

Though the metal itself isn't rainbow colored, it is called this because of its multi-colored compounds. Because iridium is very resistant to corrosion, the standard meter bar was made of 90 percent platinum and 10 percent iridium. This bar was replaced as the definition of a meter in , though. The meter was redefined in terms of the orange-red spectral line of krypton. However, the international prototype kilogram , which defines a kilogram, also made of a platinum and platinum-iridium alloy, is still in use around the world.

Today, iridium is commercially recovered as a byproduct of copper or nickel mining. In , despite not having yet published any scientific papers, he was elected a Fellow of the Royal Society at the young age of Although he published few papers during his career, they were of great significance — he demonstrated for example that diamond consisted solely of carbon 1. Tennant discovered elements 76 and 77, osmium and iridium respectively, by collecting insoluble black impurities derived from the treatment of platinum ore with aqua regia.

He treated them with caustic soda before carrying out an extraction step with hydrochloric acid, which was repeated a number of times. It is one of the least abundant elements in the Earth's crust — about forty times less abundant than gold. It is thought to have sunk to the Earth's core during the formation of the planet, owing to its siderophilic iron-loving nature.

Only three tonnes are produced annually, mainly as a by-product of the electrorefining process of copper and nickel, therefore making iridium an expensive commodity. Despite its rarity, iridium has found uses in technology — albeit limited ones. Its high resistance to corrosion, including under high temperatures, makes it a desirable constituent in spark plugs and engine parts, for example, in aviation applications.

Iridium is also commonly found in homogenous catalysis, with organoiridium compounds finding use in the carbonylation of methanol to acetic acid. Vaska's complex, IrCl CO [P C 6 H 5 3 ] 2 , used in oxidative addition reactions, has the unusual property of being able to reversibly bind diatomic oxygen.

The oxides of iridium have also attracted great interest in the last 10—15 years. As a heavy transition metal with partially filled 5 d orbitals, the oxides would be expected to display metallic conductivity, yet relativistic effects spin—orbit coupling to be precise on the electronic structure, drive a number of the oxides into an insulating state. It is these insulators that have been predicted to display exotic magnetic and electronic physics 4.

Its modern developments are counterbalanced by the literal impact of iridium in the much older history of our planet: one of the great global catastrophic events. The geological record is marked by the K—Pg boundary, a thin layer of sediment, which was found to contain very high levels of iridium — much higher than the natural abundance in the Earth's crust.