Iridium, properties of the atom, chemical and physical properties


Iridium, properties of the atom, chemical and physical properties.

Ir 77 Iridium

192.217(3) 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d7 6s2

Iridium is an element of the periodic system of chemical elements of D.I. Mendeleev with atomic number 77. It is located in the 9th group (according to the old classification - a secondary subgroup of the eighth group), the sixth period of the periodic system.

Iridium atom and molecule. Iridium formula. Structure of the iridium atom

Isotopes and modifications of iridium

Properties of iridium (table): temperature, density, pressure, etc.

Physical properties of iridium

Chemical properties of iridium. Iridium interaction. Chemical reactions with iridium

Obtaining iridium

Applications of iridium

Table of chemical elements D.I. Mendeleev

Silver market

Global silver demand is forecast to reach 1 billion ounces in 2021, up 11% year-on-year and at an eight-year high, driven primarily by industrial end users. Industrial demand is estimated to grow 9% year-on-year to 510 million ounces this year (Source: The Silver Institute), and the introduction of 5G technology in consumer electronics is expected to boost silver sales.

However, the surplus in the silver market is expected to remain, which will limit the price upside to some extent. Silver traded sideways before falling, but it outperformed gold last week.

Iridium atom and molecule. Iridium formula. Structure of the iridium atom:

Iridium (Latin Iridium, from ancient Greek ἶρις - “rainbow”) is a chemical element of D. I. Mendeleev’s periodic system of chemical elements with the designation Ir and atomic number 77. Located in the 9th group (according to the old classification - secondary subgroup of the eighth group), the sixth period of the periodic table.

Iridium is a metal. Belongs to the group of transition metals, as well as precious metals and platinum group metals.

As a simple substance, iridium under normal conditions is a very hard, refractory, silvery-white metal.

The iridium molecule is monatomic.

Chemical formula of iridium Ir.

The electronic configuration of the iridium atom is 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d7 6s2. The ionization potential (first electron) of the iridium atom is 865.19 kJ/mol (8.96702(22) eV).

Structure of the iridium atom. The iridium atom consists of a positively charged nucleus (+77), around which 77 electrons move through six shells. In this case, 75 electrons are in the internal level, and 2 electrons are in the external level. Since iridium is located in the sixth period, there are only six shells. First, the inner shell is represented by the s-orbital. The second - the inner shell is represented by s- and p-orbitals. The third and fifth – inner shells are represented by s-, p- and d-orbitals. The fourth - the inner shell is represented by s-, p-, d- and f-orbitals. The sixth - outer shell is represented by the s-orbital. At the internal energy level of the iridium atom in the 5d orbital there are four paired electrons and three unpaired electrons. At the outer energy level of the iridium atom, there are two paired electrons in the 6s orbital. In turn, the nucleus of an iridium atom consists of 77 protons and 115 neutrons. Iridium belongs to the elements of the d-family.

The radius of the iridium atom (calculated) is 180 pm.

The atomic mass iridium atom is 192.217(3) a. eat.

Iridium, along with osmium, has the highest density among all simple substances.

Iridium is the rarest metal on Earth. Its content in the earth's crust is 4.0×10-8%.

Iridium, properties of the atom, chemical and physical properties

Use, application of metal

The production of crystals is not complete without crucibles made of precious metal.

It is used in precision instrument parts and as a coating for electrical contacts.

In long-life spark plugs they are used as electrodes.

The advantage of such spark plugs is the lightning-fast acceleration of the engine and its stable operation. There is no risk of loss of spark; such spark plugs have excellent anti-corrosion properties. There is only one drawback - the price...

Metal is used for the “eternal” nibs of fountain pens.

Economical: in some countries, instead of expensive iridium, they use an alloy of niobium with rhenium - it is almost as wear-resistant, but in appearance it differs little from iridium.

Iridium is an excellent catalyst, like all its platinum metal relatives. However, the high price limits its use.

Organic synthesis is now impossible without iridium catalysts. Work on organic synthesis received the Nobel Prize in Chemistry. To make it clear, organic synthesis will make it possible to switch to “green chemistry”, abandon the use of fossil resources, and switch to renewable resources.

The kilogram standard is created from a platinum-iridium alloy and is stored in France.

Informative: don’t argue if you see in Russia, at the All-Russian Research Institute of Metrology, the international standard of the kilogram. 6 such copies of that French standard were made.

An alloy of iridium and titanium is used in deep-sea pipelines.

The Ir-192 isotope is used in flaw detectors and thickness gauges (portable).

Fabulous prospects for iridium in medicine

Pacemakers use an iridium-platinum alloy.

Oncologists use the iridium isotope Ir-192 as a source of gamma radiation. It is used to treat breast and prostate cancer (in the early stages of the disease).

Methods have been developed for the treatment of epilepsy, Parkinson's disease, and schizophrenia by introducing iridium electrodes into the brain. The method of implanting microelectrodes opens up bright prospects for creating prosthetic eyes and hearing aids.

Properties of iridium (table): temperature, density, pressure, etc.:

Detailed information on the website ChemicalStudy.ru

100General information
101NameIridium
102Former name
103Latin nameIridium
104English nameIridium
105SymbolIr
106Atomic number (number in table)77
107TypeMetal
108GroupPrecious, transition metal, platinum group metal
109OpenSmithson Tennant, Great Britain, 1803
110Opening year1803
111Appearance, etc.Very hard, refractory, silvery-white metal
112OriginNatural material
113Modifications
114Allotropic modifications
115Temperature and other conditions for the transition of allotropic modifications into each other
116Bose-Einstein condensate
1172D materials
118Content in the atmosphere and air (by mass)0 %
119Content in the earth's crust (by mass)4,0·10-8 %
120Content in seas and oceans (by mass)
121Content in the Universe and space (by mass)2,0·10-7 %
122Abundance in the Sun (by mass)2,0·10-7 %
123Content in meteorites (by mass)0,000054 %
124Content in the human body (by weight)
200Properties of the atom
201Atomic mass (molar mass)192.217(3) a. e.m. (g/mol)
202Electronic configuration1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d7 6s2
203Electronic shellK2 L8 M18 N32 O15 P2 Q0 R0

204Atomic radius (calculated)180 pm
205Empirical atomic radius*135 pm
206Covalent radius*141 pm
207Ion radius (crystalline)Ir 3+
82 (6) pm,

Ir 4+

76.5 (6) pm,

Ir 5+

71 (6) pm

(in parentheses the coordination number is indicated - a characteristic that determines the number of nearest particles (ions or atoms) in a molecule or crystal)

208Van der Waals radius
209Electrons, Protons, Neutrons77 electrons, 77 protons, 115 neutrons
210Family (block)d-family element
211Period in the periodic table6
212Group on the periodic table9th group (according to the old classification - a secondary subgroup of the 8th group)
213Emission spectrum
300Chemical properties
301Oxidation states-3, -1, 0, +1, +2, +3, +4, +5, +6, +7, +8, +9
302ValenceI, II, III, IV, V, VI
303Electronegativity2.2 (Pauling scale)
304Ionization energy (first electron)865.19 kJ/mol (8.96702(22) eV)
305Electrode potentialIr3+ + 3e– → Ir, Eo = +1.0 V
306Electron affinity energy of an atom151 kJ/mol
400Physical properties
401Density*22.56 g/cm3 (at 20 °C and other standard conditions , state of matter – solid),
19 g/cm3 (at melting point 2446 °C and other standard conditions , state of matter – liquid)
402Melting temperature*2446 °C (2719 K, 4435 °F)
403Boiling temperature*4130 °C (4403 K, 7466 °F)
404Sublimation temperature
405Decomposition temperature
406Self-ignition temperature of a gas-air mixture
407Specific heat of fusion (enthalpy of fusion ΔHpl)*41.12 kJ/mol
408Specific heat of evaporation (enthalpy of boiling ΔHboiling)*564 kJ/mol
409Specific heat capacity at constant pressure0.131 J/g K (at 0-100 °C)
410Molar heat capacity25.1 J/(K mol)
411Molar volume8.54 cm³/mol
412Thermal conductivity147 W/(mK) (at standard conditions ),
147 W/(mK) (at 300 K)
500Crystal cell
511Crystal grid #1
512Lattice structureCubic face centered

513Lattice parameters3.840 Å
514c/a ratio
515Debye temperature430 K
516Name of space symmetry groupFm_3m
517Symmetry space group number225
900additional information
901CAS number7439-88-5

Note:

205* The empirical radius of iridium according to [1] and [3] is 136 pm.

206* The covalent radius of iridium according to [1] and [3] is 141±6 pm and 127 pm, respectively.

401* The density of iridium according to [3] and [4] is 22.65 / 22.56±0.01 g/cm3 (at 0 °C and other standard conditions , the state of matter is a solid) and 22.562 g/cm3 (at 20 °C and other standard conditions , the state of matter is a solid) respectively.

402* The melting point of iridium according to [3] and [4] is 2466 °C (2739 K, 4471 °F) and 2450 °C (2723.15 K, 4442 °F), respectively.

403* The boiling point of iridium according to [3] and [4] is 4428 °C (4701 K, 8002 °F) and 4380 °C (4653.15 K, 7916 °F), respectively.

407* The specific heat of fusion (melting enthalpy ΔHmelt) of iridium according to [3] and [4] is 26.0 kJ/mol and 26.4 kJ/mol, respectively.

410* The specific heat of evaporation (boiling enthalpy ΔHboil) of iridium according to [3] and [4] is 610 kJ/mol and 612.5 kJ/mol, respectively.

Platinum market

Last week, the price of platinum rose to a six-year high. From a technical perspective, the price has broken through the 2016 high and is now heading toward potential resistance at $1,290/oz. A price rally may be the result of a temporary reduction in liquidity in the market. The closure of the Anglo American Platinum plant last year resulted in reduced production of refined platinum, and additional market purchases by Anglo have further reduced the availability of the metal.

However, rental rates have fallen since a sharp jump in April last year, confirming that long-term supply should not be a concern. Despite supply disruptions in South Africa, weak industrial demand has kept the market surplus in 2021 and is expected to remain so for the foreseeable future.

Investment in platinum helped absorb much of the surplus in 2020, so if this level of demand continues into 2021, the price could gain support.

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