There’s a particular belief that a giant asteroid struck the Earth 65 million years ago, leaving behind a thin iridium-rich clay layer. Asteroids and meteors have large concentrations of iridium. It has been suggested as well that the asteroid wiped off the dinosaurs. While you might not believe the folklore, iridium is one of the rarest elements. Curious about its various properties, let’s start with, is Iridium Magnetic?
We start by answering this question. The discussion of iridium’s electrical conductivity, radioactivity, and common locations follows. Before answering frequently asked questions, we highlight iridium’s uses and properties in this article’s final section.
Is Iridium Magnetic or Non-magnetic?
Iridium is a paramagnetic metal that repels magnets on both magnetic field poles while being only weakly attracted to them. Three of its nine valence electrons are unpaired. A magnetic field is produced due to the iridium electrons’ orbital motion and spin. Iridium contains unpaired electrons that behave like tiny magnets with a distinct magnetic moment.
The majority of transition metals exhibit paramagnetic properties. As the number of unpaired electrons increases, so do the transition metals’ paramagnetic properties. Yes, iridium belongs to the platinum (transition) group of metals. As a result, the number of unpaired electrons determines the size of the magnetic moment.
In period six of the periodic table, iridium is a transition metal between osmium and platinum. As a result, it is categorized with group nine’s platinum metals.
Does Iridium Conduct Electricity?
Iridium is an excellent electrical conductor. It is a common component in electronics because of its high electrical conductivity. Iridium rapidly gives up its nine valence electrons for bonding. Valence electrons are electrons in the outer shell of an atom that are free to move about. That means iridium has several free electrons that can carry electric charge.
Iridium has a face-centered cubic crystal structure. The crystal structure of iridium allows the free electrons to travel through it swiftly. Iridium is charged when an electric field comes into touch with it. As the freed electrons push against one another, they pass an electric current charge.
In the video below, you can observe the Face-Centred Cubic Crystal System (fcc) – Bravais Lattice
Is Iridium Radioactive?
Iridium is both stable and radioactive. It is not radioactive in its natural state. Iridium-193 (62.7%) and Iridium-191 (37.3%) are the two isotopes of natural iridium. The two isotopes are not radioactive. More forms of an iridium element exist as isotopes. However, the isotopes vary from one another based on their mass number.
Iridium has about ten radioactive isotopes. However, iridium-192, which has a half-life of 74 days, is the most significant radioactive isotope. One-half of the Iridium-192 atom decays into other stable forms, taking 74 days.
Iridium (Ir-191) metal forms isotope-192, making it an artificial radioactive element. In a nuclear reactor, neutrons are used to bombard the iridium-191, which absorbs the extra electron forming iridium-192. Iridium-192 decays unstablely and produces gamma and beta rays.
Despite being radioactive, iridium-192 has the following uses.
- It is used in the medical field for several purposes, including brachytherapy for treating different cancers.
- Non-destructive testing, or NDT, is where Ir-192 is most common.
- Ir-192 is widely used as a radiotracer in the oil business, albeit on a modest scale.
- Iridium-192 implants are usually placed in the head and breast for medical purposes.
Where is Iridium Found?
Pure Iridium does not occur in nature. Since iridium frequently occurs in volcanic flows, the Earth’s core might be a significant source. The earth’s crust, however, contains less iridium than meteorites do. Iridium also exists in naturally occurring alloys with noble metals like platinum and osmium. Iridium is manufactured commercially as a byproduct of nickel, copper, and other platinum metals.
Australia, Brazil, the United States, and Myanmar (Burma) are a few countries that have iridium ores. Most Iridium is mined commercially, nevertheless, in South Africa. The sulfide layers in mafic igneous rocks, which also happen to contain a lot of platinum group metals, are where it is mined.
Smithson Tennant discovered iridium in the residues of platinum ores in 1803. He was trying to figure out how to purify platinum. Therefore, after dissolving the native platinum ore in Aqua Regia, a black residue was left. He identified the residue as iridium after processing it with alkalis and acids.
Iridium metal is available in different forms.
- Disc: Iridium metal is cast into a disc from liquid form before being stamped into the desired shape. The size of the discs varies depending on the degree of flattening.
- Granules: Iridium ingots are ground to create iridium metal granules. The granules are used in various items, such as paints and rubber.
- Wire: Iridium has numerous uses in wire form. One of them is the manufacture of jewelry, such as earrings. Power equipment, electrical grids, computers and electronic equipment, and other uses.
- Sheet or slab: Mostly found in different sizes and thicknesses. Due to the metal’s stiffness, iridium sheets and slabs can keep their flat surface.
- Powder: Because grinding iridium metals requires a lot of work and is expensive, it is uncommon to find it in powder form. Iridium powder is commonly used to make inorganic and organic jewelry, glass, flint glass manufacturing, and water treatment.
- Pellets: Iridium pellets serve primarily in jewelry design and as a radiation source in medicine for medical diagnosis or therapy.
Properties of Iridium
Iridium is a chemical element with the symbol Ir and atomic number 77. It has 77 protons and 115 neutrons per atom.
|-Iridium ore is white or gray. When alloyed with other metals, it is shiny and silvery white. However, Iridium salts have vibrant colors.||-Reacts with cyanide salts in the presence of oxygen.|
|-High density of 22.56 g/cm³.||-Does not react to water or moisture.|
|-Hard and brittle metal.||-Highly resistant to corrosion.|
|-High electrical conductivity.||-Does not generally react with acid.|
|-Melting point of 4435°F (2446°C).||-Forms brightly colored salts.|
|-Boiling point 8002°F (4428°C).|
Uses of Iridium
The word “iridium” is derived from the Greek “iris” (rainbow). It is a valuable industrial metal that is scarce. Iridium is harder and more brittle than other metals, making it more challenging to work with. Due to its high cost, iridium is often only used in limited quantities.
Here are a few applications for iridium.
- Iridium is often used as an antiferromagnetic layer in magnetic recording due to its high melting point and low reactivity.
- Iridium has applications in pen tips, compass bearings, surgical pins, and pivots in an alloy with osmium.
- 10% iridium and 90% platinum produce standard meter bars.
- Iridium is used to produce premium spark plugs for general aviation aircraft. In airplane combustion engines, the fuel-air mixture is ignited by spark plugs.
- Iridium is used to manufacture crucibles or molten containers for substances that demand high melting temperatures.
- It creates LED panels and backlit displays for digital gadgets like iPads and iPhones.
- Iridium is a component of the chloralkali process, which produces chlorine.
- Although iridium can be used in jewelry, only minimal amounts are required to ensure long-lasting jewelry sets. Due to its scarcity, iridium is far more expensive than gold or platinum.
Iridium has unpaired electrons, which makes it paramagnetic. Magnets only slightly attract iridium, but they also strongly repel it. Iridium has a face-centered cubic crystal structure, and the unpaired free-moving electrons pass through it, carrying an electric charge.
Iridium has two stable isotopes. However, despite this, man has created a radioactive isotope, which is intriguing. Radioactive iridium-192 is produced by subjecting stable iridium-191 to a nuclear reactor.
Frequently Asked Questions
Is iridium harmful to humans?
Because it doesn’t react with tissue, iridium in its metallic state is not harmful to your health. Iridium powder, however, is hazardous to handle because it is irritating and very flammable. Fortunately, the vast majority of iridium compounds are insoluble, which makes body absorption challenging. Iridium-192 exposure, however, can raise the danger of cancer. External radiation exposure can result in burns, radiation sickness, and even death.
How do you identify iridium?
Iridium cannot be identified chemically in a simple way. However, X-ray fluorescence or solid-phase inductively coupled plasma (ICP) analysis would be the simplest. Melting powdered iridium in zinc and then dissolving it in hydrochloric acid is more complex. Undertake ICP liquid testing after boiling the acid off.
Does iridium react with water?
Iridium does not react with water under normal circumstances. Acids also don’t cause it to react—even aqua regia. When heated, iridium forms iridium (IV) oxide instead of reacting with air. Iridium reacts with salts such as potassium and sodium cyanide in high temperatures. Iridium (VI) iridium, which is highly corrosive, is created when metallic iridium combines with fluorine gas. When exposed to halogen elements, iridium reacts to form trihalides.
How can you separate gold from iridium?
Iridium is combined with three parts of silver at the St. Petersburg Mint. The alloys are then melted in large crucibles made of black lead and given some time to cool. Iridium granules sink to the bottom because it is denser than gold.