Iridium is a transitional white element that is a very rare silver-white hard, brittle metallic element. Let us examine Iridium facts in detail.
Iridium(Ir) solid is only corrosive to select molten salts and Halogens. The measurements of density, Ir, a metal belonging to the platinum group, is commonly regarded as the 2nd densest element (behind Os). At temperatures of 2000 °C, the metal resists corrosion the best.
Let us discuss the chemical characteristics of iridium, such as its atomic symbol, electronic configuration, boiling point, ionization energy, isotopes, and allotropic forms.
Iridium symbol
A chemical element is briefly described using its symbol. Let us look at the Iridium symbol.
Iridium is a periodic table element with the symbol “Ir”. The Latin word Iris means rainbow(Greek goddess) and refers to the iridium metal and the vibrant colours of its salt.
Iridium group in periodic table
The periodic table defines a group as an elemental column. Let us take a look at the iridium group prediction.
Iridium (Ir) is found in the 9th group of the periodic table. The group is subdivided according to the number of electrons in the final electronic shell. It has 9 electrons in its outermost (s and d) shell, which places it in group 9 of the periodic table.
Iridium period in periodic table
A row of the periodic table has a predetermined number of chemical elements in a particular period. Let us consider the iridium period.
Iridium (Ir) belongs to the 6th period of the periodic table.
Iridium block in periodic table
The elements that make up the block share comparable physical and chemical characteristics. Let us check the block of iridium.
Iridium is located in blocks d and f. This is because its valence electrons reside in electronic shells d and f, which are the last shells of the element. It falls within the transition element category.
Iridium atomic number
Blocks of elements are grouped together according to their chemical and physical properties. Let us talk about the Iridium atomic number.
Atomic number 77 belongs to the element iridium. It is made up of 77 protons and 77 electrons.
Iridium atomic Weight
All the isotopes of an element and their proportionate abundances determine its atomic weight. Let us discuss the atomic weight of iridium.
Iridium has an atomic weight of 192.217 g/mol.
Iridium Electronegativity according to Pauling
An atom’s electronegativity is determined by how successfully it obtains electron pairs from other atoms.. Let us examine the iridium electronegativity value.
Iridium has a Pauling electronegativity value of 2.2, like some other 9th-group elements.
Iridium atomic Density
The number of atoms in an element per unit volume is expressed as its atomic density. Let us check the atomic density of iridium.
Iridium should have a density of 22.56 g/cm3 at room temperature. Because of their electron configuration, they are extremely dense. As soon as it melts and reaches its melting point, it transforms into a liquid with a density of 19 g/cm3.
Iridium melting point
When a substance melts, its melting point is its temperature. Let us look at the melting point of iridium.
The melting point of iridium is 2719 K (2446 °C, 4435 °F).
Iridium boiling point
A substance begins to boil at its boiling point when it is liquid. Let us find out what the boiling point of iridium is.
The boiling point of iridium is 4403 K (4130 °C, 7466 °F). It has the 10th–highest boiling temperature of any element and turns into a superconductor below 273.010 °C (0.14 K; 459.418 °F).
Iridium Vanderwaals radius
The separation between two atoms of the same element kept together by their nuclei’s attraction is known as a Vander Waals radius. Let us look at the iridium’s Vander Waals radius.
Iridium has a van der Waals radius of 229 pm (1pm=1*10‑12 m).
Iridium ionic radius
Ionic radii in crystal lattice are half as far apart as atomic ions represent ionic radius. Let us look at the ionic radius of iridium.
Iridium has an ionic radius of 0.63Å(+4). The table below shows the numerous coordination centers and ionic radii of iridium:
| Iridium Ion(Irn+ ) | Coordinating Structure | Ionic Radius (1pm=1*10‑12 m) |
| Ir(III) | 6-coordinate, octahedral | 82pm |
| Ir(IV) | 6-coordinate, octahedral | 76.5pm |
| Ir(V) | 6-coordinate, octahedral | 71pm |
Iridium isotopes
Isotopes have a fixed amount of protons, but their neutron counts fluctuate. Let us check the iridium isotopes.
Iridium has 36 radioisotopes and two naturally occurring isotopes (191&193), with 192-Ir with the longest half-life (73.83 days).The most stable is 192m2Ir, which has a half-life of 241 years. The radioisotope Ir-192 is used in gamma radiography to examine metals without causing damage.
Only stable isotopes are discussed in this section:
| Iridium Isotope | Natural Abundance | Half-life | Emitting particles | No. of Neutron |
| 188Ir | Synthetic | 1.73 d | β+ | 111 |
| 189Ir | Synthetic | 13.2 d | EC | 112 |
| 190Ir | Synthetic | 11.8 d | β+ | 113 |
| 191Ir | 37.3% | Stable | Stable | 114 |
| 192Ir | Synthetic | 73.827 d | β− EC | 115 |
| 193Ir | 62.7% | Stable | Stable | 116 |
| 193mIr | Synthetic | 10.5 d | IT | 116 |
| 194Ir | Synthetic | 19.3 h | β− | 117 |
Iridium electronic shell
The number of electrons in each of the electronic shells that surround the nucleus is fixed. Let us investigate the Iridium electronic shell.
Iridium’s nucleus is surrounded by an electronic shell made up of 2, 8, 18, 32, 15, and 2 orbitals.
Iridium electron configurations
The electron configuration of an element refers to how its electrons are arranged within its orbitals. Let us look at Iridium’s electron configurations.
Iridium’s electron configurations are as follows: 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 4f14 5d7 6s2 or [Xe] 4f14 5d7 6s2.
Iridium energy of first ionisation
A last orbital electron must be removed in order to release the first ionisation energy. Let us examine iridium’s first ionisation energy.
Iridium’s first electrons must be removed with 880 kJ/mol ionization energy. The 6s orbital, which is far from the nucleus and has a low force of attraction, can be removed with less energy because of this: Ir + IE → Ir+ + e– ([Xe] 4f14 5d7 6s2; Ir→Ir1+).
Iridium energy of second ionisation
The 2nd ionisation energy is the quantity of energy necessary to eliminate a 2nd electron from the Positive ion. Let us check the second ionization energy of iridium.
Iridium’s second ionization energy is 1600 kJ/mol. Since an electron requires more energy to be extracted from a partially full orbital, its second ionization is much higher than its first: X+ → X2+ + e– ([Xe] 4f14 5d7 6s1; Ir1+→Ir2+).
Iridium energy of third ionisation
The third ionization energy creates the third ionization energy by removing the third electron from the +2 ion. Let us calculate the third ionization energy of iridium.
Iridium’s third ionisation energy is 2700 kJ/mol. The third electron must be removed from the outermost X2+ → X3+ + e– ([Xe] 4f14 5d7 6s2; Ir2+→Ir3+)) orbitals using this energy. The third ionisation energy is very high because a third electron must be taken out of the configuration of Ir2+.
Iridium oxidation states
The charge that develops on the element during bond formation is known as the oxidation state. Let us examine Iridium’s oxidation states.
Iridium can create compounds in a variety of oxidation states, such as −3, −1, 0, +1, +2, +3, +4, +5, +6, +7, +8, +9. The most typical ones are, however, +3 and +4. IrO2 is the only transition metal oxide with good characterization. It is a blue-black solid that can produce Ir2O3 when it reacts with HNO3.
The following table displays several Ir molecules’ oxidation states:
| Oxidation Statesof Ir ion | Molecule of Ir |
| -3 | [Ir(CO)3]3− |
| -1 | [Ir(CO)3(PPh3)]− |
| 0 | Ir4(CO)12 |
| +1 | [Ir(CO)Cl(PPh3)2] |
| +2 | IrCp2 |
| +3 | IrCl3 |
| +4 | IrO2 |
| +5 | Ir4F20 |
| +6 | IrF6 |
| +7 | [(η2-O2)IrO2]+ |
| +8 | IrO4 |
| +9 | [IrO4]+ |
Iridium CAS number
CAS registration or a CAS number can identify any element as being unique. Let us check the Iridium CAS number.
The iridium molecule has the CAS number 7439-88-5.
Iridium ChemSpider ID
Chem Spider ID is the specific number the Royal Society of Science assigned to a certain element to identify it by its character. Let us check the Iridium Chemspider ID.
The Chemspider ID for iridium is 22367. Iridium information is provided by ChemSpider’s database using this ID.
Iridium allotropic forms
The physical characteristics of allotropes differ from their chemical counterparts. Let us talk about Iridium in its allotropic state.
Iridium does not exhibit an allotropic form. Since it is radioactive by nature, no additional allotropes can be created.
Iridium chemical classification
The periodic table divides the elements into groups based on their chemical makeup. Let us see how iridium is classified chemically.
- Iridium has the second-highest elasticity modulus of any metal.
- As catalysts, iridium compounds are employed.
- The electron affinity of iridium is 151 kJ/mol.
- Iridium rapidly reacts with sulfur at atmospheric pressure to form iridium disulfide.
Iridium state at room temperature
The state in which an element can reside under standard pressure and temperature is known as the physical state of an atom. Let us check the state of Ir at room temperature.
Iridium is solid at standard or room temperature(20°C). Iridium is a valuable, silver-white metal that can be worked at a white heat between 1,200° and 1,500° despite being hard and brittle.
Iridium’s solid-state structure is a face-centered cubic shape. The Unit Cell of the Crystal structure might be used to describe it.
Is Iridium paramagnetic?
The propensity of magnetization to point in the direction of the magnetic field is known as paramagnetism. Let us examine the paramagnetic characteristics of iridium.
Iridium has paramagnetic properties due to unpaired electrons. The molar magnetic susceptibility of the iridium metal is +25.6 × 10−6 cm3/mol, which makes it paramagnetic (298 K).
Conclusion
The corrosion resistance of iridium is the highest among all metallic elements, as it is not affected by nearly all acids, molten metals, silicates, or aqua regia at high temperatures. It is found in natural deposits either by itself or in combination with platinum and other related metals.
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