Iridium (Ir)

Iridium is the 77th element in the periodic table and has a symbol of Ir and atomic number of 77. It has an atomic weight of 192.217 and a mass number of 193. Iridium has seventy-seven protons and one hundred sixteen neutrons in its nucleus, and seventy-seven electrons in six shells. It is located in group nine, period six and block d of the periodic table. Very hard and brittle, silvery metallic transition element. It has a yellowish cast to it. Salts of iridium are highly colored. It is the most corrosion resistant metal known, not attacked by any acid, but is attacked by molten salts. There are two natural isotopes of iridium, and 4 radioisotopes, the most stable being Ir-192 with a half-life of 73.83 days. Ir-192 decays into Platinum, while the other radioisotopes decay into Osmium. Iridium is used in high temperature apparatus, electrical contacts, and as a hardening agent for platinumpy. Discovered in 1803 by Smithson Tennant in England. The name comes from the Greek word iris, which means rainbow. Iridium metal is generally non-toxic due to its relative unreactivity, but iridium compounds should be considered highly toxic.

Atomic Number	77
Atomic Weight	192.217
Mass Number	193

Group	9
Period	6
Block	d

Protons	77 p⁺
Neutrons	116 n⁰
Electrons	77 e^-

Physical Properties

Atomic Radius	135 pm 240 pm
Molar Volume	8.54 cm³/mol
Covalent Radius	122 pm 115 pm 107 pm 141 pm
Metallic Radius	127 pm 136 pm
Ionic Radius	68 pm 62.5 pm 57 pm
Crystal Radius	82 pm 76.5 pm 71 pm
Van der Waals Radius	200 pm 213 pm 236 pm 284 pm
Density	22.5622 g/cm³ 19,000 kg/m³

Chemical Properties

Energy

Proton Affinity
Electron Affinity	1.5638 eV/particle
Ionization Energy	8.96702 eV/particle 17 eV/particle 28 eV/particle 40 eV/particle 57 eV/particle 72 eV/particle 89 eV/particle 105 eV/particle 123 eV/particle 194.8 eV/particle 217 eV/particle 240 eV/particle 264 eV/particle 303 eV/particle 329 eV/particle 356 eV/particle 407 eV/particle 445 eV/particle 472 eV/particle 510 eV/particle 560 eV/particle 610 eV/particle 670 eV/particle 720 eV/particle 770 eV/particle 820 eV/particle 870 eV/particle 920 eV/particle 980 eV/particle 1,030 eV/particle 1,080 eV/particle 1,331 eV/particle 1,381 eV/particle 1,436 eV/particle 1,493 eV/particle 1,548 eV/particle 1,603 eV/particle 1,684 eV/particle 1,739 eV/particle 1,801 eV/particle 1,857 eV/particle 2,083 eV/particle 2,139 eV/particle 2,201 eV/particle 2,258 eV/particle 2,435 eV/particle 2,500 eV/particle 2,656 eV/particle 2,720.4 eV/particle 4,540 eV/particle 4,668 eV/particle 4,806 eV/particle 4,952 eV/particle 5,092 eV/particle 5,229 eV/particle 5,466 eV/particle 5,609 eV/particle 5,765 eV/particle 5,910 eV/particle 6,315 eV/particle 6,441 eV/particle 6,580 eV/particle 6,708 eV/particle 7,274 eV/particle 7,421 eV/particle 7,710 eV/particle 7,850 eV/particle 17,040 eV/particle 17,390 eV/particle 17,770 eV/particle 18,120 eV/particle 20,210 eV/particle 20,650 eV/particle 21,200 eV/particle 21,556.6 eV/particle 86,438.9 eV/particle 88,113.3 eV/particle

Heat of Vaporization	604 kJ/mol
Heat of Fusion	27.61 kJ/mol
Heat of Formation	669 kJ/mol
Electrons

Electron Shells	2, 8, 18, 32, 15, 2

Valence Electrons	2 ⓘ

Electron Configuration	[Xe] 4f¹⁴ 5d⁷ 6s²ⓘ 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 4f¹⁴ 5d⁷ 6s²

Oxidation States	-3, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9
Electronegativity	9.96 eV/particle 0.25106 2.2
Electrophilicity Index	1.872465121129725 eV/particle
States of Matter

Phase	Solid
Gas Phase
Boiling Point	4,701.15 K
Melting Point	2,719.15 K
Critical Pressure
Critical Temperature
Triple Point
Visual
Iridium is a Silver. Ir has a CPK of #ff1493, Jmol of #175487, and MOLCAS GV of #175487. The Appearance of Element 77 is silvery white.
Color	Silver #ff1493 #175487 #175487
Appearance	silvery white
Refractive Index
Thermodynamic Properties
Thermal Conductivity	147 W/(m K)
Thermal Expansion	0.0000064 1/K
Molar Heat Capacity	25.1 J/(mol K)
Specific Heat Capacity	0.131 J/(g⋅K)
Heat Capacity Ratio (Adiabatic Index)
Electrical Properties
Type	Conductor
Electrical Conductivity	21 MS/m
Electrical Resistivity	0.00000004699999999998 Ω*m
Superconducting Point	0.11 K
Magnetism
Type	paramagnetic
Magnetic Susceptibility (Mass)	0.00000000167 m³/Kg
Magnetic Susceptibility (Molar)	0.000000000321 m³/mol
Magnetic Susceptibility (Volume)	0.0000377
Magnetic Ordering
Curie Point
Neel Point
Structure
The Crystal Structure of Iridium is FCC. The lattice constant of Ir is 3.84 Å. The lattice angles of Element 77 are π/2, π/2, π/2.
Crystal Structure	Face Centered Cubic (FCC)
Lattice Constant	3.84 Å
Lattice Angles	π/2, π/2, π/2
Mechanical Properties
Iridium has a Brinell of 1670 MPa, Mohs hardness of 6.5 MPa, and Vickers of 1760 MPa. The Bulk Modulus of Ir is 320 GPa. The Shear Modulus of Element 77 is 210 GPa. The Young Modulus of Iridium (Ir) is 528 GPa. The Poisson Ratio of Iridium is 0.26. The Speed of Sound of Ir is 4825 m/s.
Hardness	1,670 MPa 6.5 MPa 1,760 MPa
Bulk Modulus	320 GPa
Shear Modulus	210 GPa
Young's Modulus	528 GPa
Poisson Ratio	0.26
Speed of Sound	4,825 m/s
Classification
The CAS Group of Iridium is VIIIA. The IUPAC Group of Ir is VIII. The Glawe Number of Element 77 is 62. The Mendeleev Number of Iridium (Ir) is 65. The Pettifor Number of Iridium is 65. The Geochemical Class of Ir is noble metal. The Goldschmidt Class of Element 77 is siderophile.
Category	Transition metals, Transition metals
CAS Group	VIIIA
IUPAC Group	VIII
Glawe Number	62
Mendeleev Number	65
Pettifor Number	65
Geochemical Class	noble metal
Goldschmidt Class	siderophile

Other

The Dipole Polarizability of Iridium is 54 plus or minus 7 a₀. Ir has a C6 Dispersion Coefficient (GB) of 522 a₀. The Allotropes of Element 77 is . The Neutron Cross Section of Iridium (Ir) is 425. The Neutron Mass Absorption of Iridium is 0.081. The Quantum Numbers of Ir is 4F9/2. The Space Group of Element 77 is 225 (Fm_3m).

Gas Basicity
Dipole Polarizability	54 ± 7 a₀
C6 Dispersion Coefficient	522 a₀
Allotropes
Neutron Cross Section	425
Neutron Mass Absorption	0.081
Quantum Numbers	4F9/2
Space Group	225 (Fm_3m)

Isotopes of Iridium

Stable Isotopes	2
Unstable Isotopes	41
Natural Isotopes	2

¹⁶³Ir

Mass Number	163
Neutron Number	86
Relative Atomic Mass	162.994299 ± 0.000429 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life
Spin	1/2
Quadrupole Moment	0
Discovery Year
Parity	+

Decay Mode	Intensity
p (proton emission)

¹⁶⁴Ir

Mass Number	164
Neutron Number	87
Relative Atomic Mass	163.991966 ± 0.000339 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life
Spin	2
Quadrupole Moment
Discovery Year
Parity	-

Decay Mode	Intensity
p (proton emission)
α (α emission)
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)

¹⁶⁵Ir

Mass Number	165
Neutron Number	88
Relative Atomic Mass	164.987552 ± 0.00017 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life
Spin	1/2
Quadrupole Moment	0
Discovery Year
Parity	+

Decay Mode	Intensity
p (proton emission)
α (α emission)

¹⁶⁶Ir

Mass Number	166
Neutron Number	89
Relative Atomic Mass	165.985716 ± 0.000215 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	10.5 ± 2.2 ms
Spin	2
Quadrupole Moment
Discovery Year	1981
Parity

Decay Mode	Intensity
α (α emission)	93%
p (proton emission)	7%

¹⁶⁷Ir

Mass Number	167
Neutron Number	90
Relative Atomic Mass	166.981671973 ± 0.000019694 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	29.3 ± 0.6 ms
Spin	1/2
Quadrupole Moment	0
Discovery Year	1981
Parity	+

Decay Mode	Intensity
α (α emission)	43.5%
p (proton emission)	38.6%
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)

¹⁶⁸Ir

Mass Number	168
Neutron Number	91
Relative Atomic Mass	167.979960978 ± 0.000059277 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	230 ± 50 ms
Spin	2
Quadrupole Moment
Discovery Year	1978
Parity

Decay Mode	Intensity
α (α emission)	100%
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)
β⁺ p (β⁺-delayed proton emission)

¹⁶⁹Ir

Mass Number	169
Neutron Number	92
Relative Atomic Mass	168.976281743 ± 0.00002502 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	353 ± 4 ms
Spin	1/2
Quadrupole Moment	0
Discovery Year	1978
Parity	+

Decay Mode	Intensity
α (α emission)	53%
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)

¹⁷⁰Ir

Mass Number	170
Neutron Number	93
Relative Atomic Mass	169.975113 ± 0.000109 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	910 ± 150 ms
Spin	3
Quadrupole Moment
Discovery Year	1977
Parity	-

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)
α (α emission)	5.2%

¹⁷¹Ir

Mass Number	171
Neutron Number	94
Relative Atomic Mass	170.97164552 ± 0.000041295 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	3.1 ± 0.3 s
Spin	1/2
Quadrupole Moment	0
Discovery Year	1967
Parity	+

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)
α (α emission)	15%

¹⁷²Ir

Mass Number	172
Neutron Number	95
Relative Atomic Mass	171.970607035 ± 0.000034785 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	4.4 ± 0.3 s
Spin	3
Quadrupole Moment
Discovery Year	1967
Parity	-

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	98%
α (α emission)	2%

¹⁷³Ir

Mass Number	173
Neutron Number	96
Relative Atomic Mass	172.967505477 ± 0.000011316 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	9 ± 0.8 s
Spin	1/2
Quadrupole Moment	0
Discovery Year	1967
Parity	+

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	96.5%
α (α emission)	3.5%

¹⁷⁴Ir

Mass Number	174
Neutron Number	97
Relative Atomic Mass	173.966949939 ± 0.000012046 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	7.9 ± 0.6 s
Spin	2
Quadrupole Moment
Discovery Year	1967
Parity	+

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	99.5%
α (α emission)	0.5%

¹⁷⁵Ir

Mass Number	175
Neutron Number	98
Relative Atomic Mass	174.964149519 ± 0.000013295 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	9 ± 2 s
Spin	1/2
Quadrupole Moment	0
Discovery Year	1967
Parity	+

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	99.15%
α (α emission)	0.85%

¹⁷⁶Ir

Mass Number	176
Neutron Number	99
Relative Atomic Mass	175.963626261 ± 0.000008679 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	8.7 ± 0.5 s
Spin	3
Quadrupole Moment
Discovery Year	1967
Parity	+

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	96.9%
α (α emission)	3.1%

¹⁷⁷Ir

Mass Number	177
Neutron Number	100
Relative Atomic Mass	176.9613015 ± 0.000021213 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	29.8 ± 1.7 s
Spin	5/2
Quadrupole Moment
Discovery Year	1967
Parity	-

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%
α (α emission)	0.06%

¹⁷⁸Ir

Mass Number	178
Neutron Number	101
Relative Atomic Mass	177.961079395 ± 0.000020204 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	12 ± 2 s
Spin	3
Quadrupole Moment
Discovery Year	1972
Parity	+

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%

¹⁷⁹Ir

Mass Number	179
Neutron Number	102
Relative Atomic Mass	178.959117594 ± 0.000010489 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	79 ± 1 s
Spin	5/2
Quadrupole Moment
Discovery Year	1992
Parity

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%

¹⁸⁰Ir

Mass Number	180
Neutron Number	103
Relative Atomic Mass	179.959229446 ± 0.000023302 Da
G-Factor	0.5 ± 0.04
Abundance
Radioactivity	☢️ Radioactive
Half Life	1.5 ± 0.1 m
Spin	5
Quadrupole Moment
Discovery Year	1972
Parity	+

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%

¹⁸¹Ir

Mass Number	181
Neutron Number	104
Relative Atomic Mass	180.957634691 ± 0.000005631 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	4.9 ± 0.15 m
Spin	5/2
Quadrupole Moment
Discovery Year	1972
Parity	-

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%

¹⁸²Ir

Mass Number	182
Neutron Number	105
Relative Atomic Mass	181.958076296 ± 0.000022509 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	15 ± 1 m
Spin	3
Quadrupole Moment
Discovery Year	1961
Parity	+

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%

¹⁸³Ir

Mass Number	183
Neutron Number	106
Relative Atomic Mass	182.956841231 ± 0.000026486 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	58 ± 5 m
Spin	5/2
Quadrupole Moment
Discovery Year	1961
Parity	-

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%
α (α emission)

¹⁸⁴Ir

Mass Number	184
Neutron Number	107
Relative Atomic Mass	183.957476 ± 0.00003 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	3.09 ± 0.03 h
Spin	5
Quadrupole Moment	2.41 ± 0.03
Discovery Year	1960
Parity	-

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%

¹⁸⁵Ir

Mass Number	185
Neutron Number	108
Relative Atomic Mass	184.956698 ± 0.00003 Da
G-Factor	1.0384 ± 0.0052
Abundance
Radioactivity	☢️ Radioactive
Half Life	14.4 ± 0.1 h
Spin	5/2
Quadrupole Moment
Discovery Year	1958
Parity	-

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%

¹⁸⁶Ir

Mass Number	186
Neutron Number	109
Relative Atomic Mass	185.957946754 ± 0.00001774 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	16.64 ± 0.03 h
Spin	5
Quadrupole Moment	-2.55 ± 0.03
Discovery Year	1958
Parity	+

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%

¹⁸⁷Ir

Mass Number	187
Neutron Number	110
Relative Atomic Mass	186.957542 ± 0.00003 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	10.5 ± 0.3 h
Spin	3/2
Quadrupole Moment	0.941 ± 0.011
Discovery Year	1958
Parity	+

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%

¹⁸⁸Ir

Mass Number	188
Neutron Number	111
Relative Atomic Mass	187.958834999 ± 0.000010116 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	41.5 ± 0.5 h
Spin	1
Quadrupole Moment	0.484 ± 0.006
Discovery Year	1950
Parity	-

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%

¹⁸⁹Ir

Mass Number	189
Neutron Number	112
Relative Atomic Mass	188.958722602 ± 0.0000135 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	13.2 ± 0.1 d
Spin	3/2
Quadrupole Moment
Discovery Year	1955
Parity	+

Decay Mode	Intensity
ϵ (electron capture)	100%

¹⁹⁰Ir

Mass Number	190
Neutron Number	113
Relative Atomic Mass	189.960543374 ± 0.00000147 Da
G-Factor	0.01 ± 0.0025
Abundance
Radioactivity	☢️ Radioactive
Half Life	11.78 ± 0.1 d
Spin	4
Quadrupole Moment	2.87 ± 0.16
Discovery Year	1947
Parity	-

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%
e⁺ (positron emission)	0.002%

¹⁹¹Ir

Mass Number	191
Neutron Number	114
Relative Atomic Mass	190.960591455 ± 0.000001406 Da
G-Factor	0.10013333333333 ± 0.0004
Abundance	37.3 ± 0.2
Radioactivity	Stable
Half Life	Not Radioactive ☢️
Spin	3/2
Quadrupole Moment	0.816 ± 0.009
Discovery Year	1935
Parity	+

¹⁹²Ir

Mass Number	192
Neutron Number	115
Relative Atomic Mass	191.962602414 ± 0.00000141 Da
G-Factor	0.47925 ± 0.0025
Abundance
Radioactivity	☢️ Radioactive
Half Life	73.82 ± 0.014 d
Spin	4
Quadrupole Moment	2.15 ± 0.06
Discovery Year	1937
Parity	+

Decay Mode	Intensity
β⁻ (β⁻ decay)	95.24%
ϵ (electron capture)	4.76%

¹⁹³Ir

Mass Number	193
Neutron Number	116
Relative Atomic Mass	192.962923753 ± 0.000001425 Da
G-Factor	0.10866666666667 ± 0.0004
Abundance	62.7 ± 0.2
Radioactivity	Stable
Half Life	Not Radioactive ☢️
Spin	3/2
Quadrupole Moment	0.751 ± 0.009
Discovery Year	1935
Parity	+

¹⁹⁴Ir

Mass Number	194
Neutron Number	117
Relative Atomic Mass	193.965075703 ± 0.000001429 Da
G-Factor	0.39 ± 0.01
Abundance
Radioactivity	☢️ Radioactive
Half Life	19.35 ± 0.07 h
Spin	1
Quadrupole Moment	0.339 ± 0.012
Discovery Year	1937
Parity	-

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%

¹⁹⁵Ir

Mass Number	195
Neutron Number	118
Relative Atomic Mass	194.965976898 ± 0.000001431 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	2.29 ± 0.17 h
Spin	3/2
Quadrupole Moment
Discovery Year	1952
Parity	+

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%

¹⁹⁶Ir

Mass Number	196
Neutron Number	119
Relative Atomic Mass	195.968399669 ± 0.000041239 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	52 ± 1.1 s
Spin	1
Quadrupole Moment
Discovery Year	1966
Parity

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%

¹⁹⁷Ir

Mass Number	197
Neutron Number	120
Relative Atomic Mass	196.969657217 ± 0.000021588 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	5.8 ± 0.5 m
Spin	3/2
Quadrupole Moment
Discovery Year	1952
Parity	+

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%

¹⁹⁸Ir

Mass Number	198
Neutron Number	121
Relative Atomic Mass	197.972399 ± 0.000215 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	8.7 ± 0.4 s
Spin	1
Quadrupole Moment
Discovery Year	1973
Parity	-

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%

¹⁹⁹Ir

Mass Number	199
Neutron Number	122
Relative Atomic Mass	198.973807097 ± 0.000044073 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	7 ± 5 s
Spin	3/2
Quadrupole Moment
Discovery Year	1993
Parity	+

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%

²⁰⁰Ir

Mass Number	200
Neutron Number	123
Relative Atomic Mass	199.976844 ± 0.00021 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	43 ± 6 s
Spin	2
Quadrupole Moment
Discovery Year	2008
Parity	-

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)

²⁰¹Ir

Mass Number	201
Neutron Number	124
Relative Atomic Mass	200.978701 ± 0.000215 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	21 ± 5 s
Spin	3/2
Quadrupole Moment
Discovery Year	2008
Parity	+

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%

²⁰²Ir

Mass Number	202
Neutron Number	125
Relative Atomic Mass	201.982136 ± 0.000322 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	11 ± 3 s
Spin	2
Quadrupole Moment
Discovery Year	2008
Parity	-

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%

²⁰³Ir

Mass Number	203
Neutron Number	126
Relative Atomic Mass	202.984573 ± 0.000429 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life
Spin	3/2
Quadrupole Moment
Discovery Year	2009
Parity	+

Decay Mode	Intensity
β⁻ (β⁻ decay)

²⁰⁴Ir

Mass Number	204
Neutron Number	127
Relative Atomic Mass	203.989726 ± 0.000429 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life
Spin
Quadrupole Moment
Discovery Year	2011
Parity

Decay Mode	Intensity
β⁻ (β⁻ decay)
β⁻ n (β⁻-delayed neutron emission)

²⁰⁵Ir

Mass Number	205
Neutron Number	128
Relative Atomic Mass	204.993988 ± 0.000537 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life
Spin	3/2
Quadrupole Moment
Discovery Year	2012
Parity	+

Decay Mode	Intensity
β⁻ (β⁻ decay)
β⁻ n (β⁻-delayed neutron emission)

History

Iridium was discovered in 1803 by English chemist Smithson Tennant in London. Chemists who studied platinum dissolved it in aqua regia to create soluble salts and observed a small amount of a dark, insoluble residue. Smithson Tennant analyzed the insoluble residue and concluded that it must contain a new metal. From the Latin word iris meaning rainbow

Discoverers	S.Tenant, A.F.Fourcory, L.N.Vauquelin, H.V.Collet-Descoltils
Discovery Location	England/France
Discovery Year	1804
Etymology (Name Origin)	Latin: iris (rainbow).
Pronunciation	i-RID-i-em (English)

Iridium is considered to be of low toxicity

Iridium is the most corrosion-resistant metal known

Uses

Iridium is used in making crucibles and other equipment that is used at high temperatures. Iridium is also used as a hardening agent in platinum alloys. Its resistance to arc erosion makes iridium alloys ideal for electrical contacts for spark plugs. Radioactive isotopes of iridium are used in radiation therapy for the treatment of cancer. Used with osmium to tip gold pen points, to make crucible and special containers. Also to make alloys used for standard weights and measures, and heat-resistant alloys. Also as hardening agent for platinum.

Sources

Found in gravel deposits with platinum.

Abundance
Abundance in Earth's crust	0.001 mg/kg
Natural Abundance (Oceans)
Natural Abundance (Human Body)
Natural Abundance (Meteor)	0.000054 %
Natural Abundance (Sun)	0.0000002 %
Abundance in Universe	0.0000002 %

Nuclear Screening Constants

1	s	1.4881
2	p	4.4624
2	s	20.1102
3	d	13.514
3	p	21.9311
3	s	22.7942
4	d	37.2628
4	f	38.6552
4	p	35.086
4	s	34.152
5	d	58.304
5	p	53.339
5	s	51.1545
6	s	66.4334

Also Known As

Ir
element 77

Translations

Norwegian Bokmåliridium
Italianiridio
Frenchiridium
Russianиридий
GermanIridium
Catalaniridi
Spanishiridio
Norwegian Nynorskiridium
Hungarianirídium
Swedishiridium
Afrikaansiridium
Amharicኢሪዲየም
AragoneseIridio
Arabicإريديوم
Azerbaijaniİridium
BelarusianІрыдый
Bulgarianиридий
Banglaইরিডিয়াম
Bosnianiridij
CherokeeᎠᎢᎵᏗᏴᎻ
CorsicanIridiu
Czechiridium
ChuvashИриди
WelshIridiwm
Danishiridium
Greekιρίδιο
Esperantoiridio
EstonianIriidium
Basqueiridio
Persianایریدیم
Finnishiridium
FriulianIridi
IrishIridiam
GalicianIridio
ManxIriddjum
Hakka Chineseiridium
Hebrewאירידיום
Fiji HindiIridium
CroatianIridij
Upper SorbianIridium
Haitian CreoleIridyòm
Armenianիրիդիում
InterlinguaIridium
Indonesianiridium
IdoIridio
Icelandiciridín
Japaneseイリジウム
Lojbanjinmrdiridi
JavaneseIridium
Georgianირიდიუმი
KazakhИридий
Kannadaಇರಿಡಿಯಮ್
Korean이리듐
KurdishÎrîdyûm
KomiИридий
Latiniridium
LuxembourgishIridium
LimburgishIridium
LigurianIridio
LithuanianIridis
Latvianirīdijs
Malayalamഇറിഡിയം
Marathiइरिडियम
Western MariИридий
MalayIridium
Dutchiridium
OccitanIridi
Polishiryd
Western Panjabiاریڈیم
Portugueseirídio
QuechuaIridyu
Romanianiridiu
Sicilianiridiu
Serbo-CroatianIridijum
Slovakirídium
SlovenianIridij
AlbanianIridiumi
Serbianиридијум
Saterland FrisianIridium
SwahiliIridi
Tamilஇரிடியம்
Thaiอิริเดียม
Turkishİridyum
Ukrainianіридій
UrduIridium
VepsIridii
Vietnameseiridi
WarayIridyo
KalmykИридиум
Yiddishאירידיום
YorubaIridium
Chinese銥
BretonIridiom
CebuanoIridio
Macedonianиридиум
Central Kurdishئیریدیۆم
Odiaଇରିଡ଼ିଅମ
Gujaratiઈરિડીયમ
Punjabiਇਰੀਡੀਅਮ
TatarИридий
PiedmonteseIridi
Scotsiridium
SomaliIridiyaam
Cantonese銥
Belarusian (Taraskievica orthography)Ірыд
Chinese (China)铱
Chinese (Simplified)铱
Chinese (Traditional)銥
Chinese (Hong Kong SAR China)銥
Chinese (Taiwan)銥
AromanianIridiu
UzbekIridiy
Nepaliइरिडियम
KyrgyzИридий
Hindiइरीडियम
Sanskritइरिडियम
Malteseiridju
LombardIridio
Scottish GaelicIridium
Portuguese (Brazil)irídio
Newariइरिडियम
Paliइरिडियम
Teluguఇరీడియం
cdoIridium
Min Nan ChineseIridium
AsturianIridiu
Bhojpuriइरीडियम
Tibetanཨི་རི་ཌིམ།
Literary Chinese銥
Lingua Franca Novairidio
kbpƖrɩdɩyɔm
Wu Chinese铱
TagalogIridiyo
Mongolianириди
oloIridii
Northern FrisianIriidium
TajikИридий
Uyghurئىرىدىي
BavarianIridium
SardinianIrìdiu
Burmeseအိုင်ရီဒီယမ်
BashkirИридий
Moroccan Arabicإيريديوم
Egyptian Arabicاريديوم
Pashtoارېډيوم
Manipuriꯏꯔꯤꯗꯤꯌꯝ
CornishIridiom
BalineseIridium
KotavaIrdel
BikolIridyo
GandaYirediyaamu
Korean (North Korea)이리디움

Iridium on ChemicalAid

Art & Architecture Thesaurus ID	300380172
Australian Educational Vocabulary ID	scot/3533
Brockhaus Enzyklopädie online ID	iridium
CAS Registry Number	7439-88-5
CPV Supplementary	AA28
ChEBI ID	49666
ChemSpider ID	22367
Common Procurement Vocabulary	14761000
DSSTOX compound identifier	DTXCID8047636
DSSTox substance ID	DTXSID0064674
Den Store Danske ID	Iridium
Den Store Danske ID	iridium
ECHA Substance Infocard ID	100.028.269
Encyclopedia of China ID (Second Edition)	242533
Encyclopædia Britannica Online ID	science/iridium
Encyclopædia Universalis ID	iridium
Freebase ID	/m/025rw2y
French Vikidia ID	Iridium
GND ID	4162402-6
Gran Enciclopèdia Catalana ID	0117711
Great Russian Encyclopedia Online ID	2020562
HSDB ID	7067
InChI	InChI=1S/Ir
InChIKey	GKOZUEZYRPOHIO-UHFFFAOYSA-N
KBpedia ID	Iridium
Library of Congress authority ID	sh85068067
MeSH descriptor ID	D007495
NALT ID	47705
NDL Authority ID	00564222
Namuwiki ID	이리듐
National Library of Israel J9U ID	987007560422405171
OmegaWiki Defined Meaning	160503
OpenAlex ID	C528581852
PSH ID	5780
PubChem CID	23924
Quora topic ID	Iridium-metal-1
RxNorm ID	1311131
Store norske leksikon ID	iridium
Treccani ID	iridio
UNII	44448S9773
USGS Thesaurus ID	1484
Wolfram Language entity code	Entity["Mineral", "Iridium"]
WordNet 3.1 Synset ID	14666397-n
YSO ID	39350
ZVG number	8460

Iridium (Ir)

Physical Properties

Chemical Properties

Other

Isotopes of Iridium

163Ir

164Ir

165Ir

166Ir

167Ir

168Ir

169Ir

170Ir

171Ir

172Ir

173Ir

174Ir

175Ir

176Ir

177Ir

178Ir

179Ir

180Ir

181Ir

182Ir

183Ir

184Ir

185Ir

186Ir

187Ir

188Ir

189Ir

190Ir

191Ir

192Ir

193Ir

194Ir

195Ir

196Ir

197Ir

198Ir

199Ir

200Ir

201Ir

202Ir

203Ir

204Ir

205Ir