Ir Iridium – Element Information, Facts, Properties, Trends,Uses, Comparison with other elements

77
Ir
Iridium

Iridium

Element 77 of Periodic table is Iridium with atomic number 77, atomic weight 192.217. Iridium, symbol Ir, has a Face Centered Cubic structure and Silver color. Iridium is a transition metal element. Know everything about Iridium Facts, Physical Properties, Chemical Properties, Electronic configuration, Atomic and Crystal Structure.

77 Ir - Iridium | SchoolMyKids

Iridium is a chemical element with symbol Ir and atomic number 77. A very hard, brittle, silvery-white transition metal of the platinum group, iridium is generally credited with being the second densest element (after osmium) based on measured density, although calculations involving the space lattices of the elements show that iridium is denser. It is also the most corrosion-resistant metal, even at temperatures as high as 2000 °C. Although only certain molten salts and halogens are corrosive to solid iridium, finely divided iridium dust is much more reactive and can be flammable.

How to Locate Iridium on Periodic Table

Periodic table is arranged by atomic number, number of protons in the nucleus which is same as number of electrons. The atomic number increases from left to right. Periodic table starts at top left ( Atomic number 1) and ends at bottom right (atomic number 118). Therefore you can directly look for atomic number 77 to find Iridium on periodic table.

Another way to read periodic table and locate an element is by using group number (column) and period number (row). To locate Iridium on periodic table look for cross section of group 9 and period 6 in the modern periodic table.

Table of Contents

Iridium History

The element Iridium was discovered by Smithson Tennant in year 1803 in France and United Kingdom . Iridium derived its name from Iris, the Greek goddess of the rainbow

Iridium Presence: Abundance in Nature and Around Us

The table below shows the abundance of Iridium in Universe, Sun, Meteorites, Earth's Crust, Oceans and Human Body.

  Ppb by weight (1ppb =10^-7 %)
Abundance in Universe 2×10-7%
Abundance in Sun 2×10-7%
Abundance in Meteorites 5.4e-07
Abundance in Earth's Crust 4×10-8%
Abundance in Oceans N/A
Abundance in Humans N/A

Crystal Structure of Iridium

The solid state structure of Iridium is Face Centered Cubic.

The Crystal structure can be described in terms of its unit Cell. The unit Cells repeats itself in three dimensional space to form the structure.

Unit Cell Parameters

The unit cell is represented in terms of its lattice parameters, which are the lengths of the cell edges Lattice Constants (a, b and c)

a b c
383.9 383.9 383.9 pm

and the angles between them Lattice Angles (alpha, beta and gamma).

alpha beta gamma
π/2 π/2 π/2

The positions of the atoms inside the unit cell are described by the set of atomic positions ( xi, yi, zi) measured from a reference lattice point.

The symmetry properties of the crystal are described by the concept of space groups. All possible symmetric arrangements of particles in three-dimensional space are described by the 230 space groups (219 distinct types, or 230 if chiral copies are considered distinct.

Space Group Name Fm_ 3m 77 Ir Iridium - Crystal Structure | SchoolMyKids
Space Group Number 225
Crystal Structure Face Centered Cubic

Iridium Atomic and Orbital Properties

Iridium atoms have 77 electrons and the electronic shell structure is [2, 8, 18, 32, 15, 2] with Atomic Term Symbol (Quantum Numbers) 4F9/2.

Atomic Number 77
Number of Electrons (with no charge) 77
Number of Protons 77
Mass Number 192
Number of Neutrons 115
Shell structure (Electrons per energy level) [2, 8, 18, 32, 15, 2]
Electron Configuration [Xe] 4f14 5d7 6s2
Valence Electrons 5d7 6s2
Oxidation State -3;-1
1;2;3;4;5;6;7;8;9
Atomic Term Symbol (Quantum Numbers) 4F9/2

Shell Structure of Iridium - Electrons per energy level

77 Ir Iridium - Electron Shell Structure | SchoolMyKids
n s p d f
1 K 2
2 L 2 6
3 M 2 6 10
4 N 2 6 10 14
5 O 2 6 7
6 P 2

Ground State Electronic Configuration of Iridium - neutral Iridium atom

The ground state electronic configuration of Neutral Iridium atom is [Xe] 4f14 5d7 6s2. The portion of Iridium configuration that is equivalent to the noble gas of the preceding period, is abbreviated as [Xe]. For atoms with many electrons, this notation can become lengthy and so an abbreviated notation is used.This is important as it is the Valence electrons 4f14 5d7 6s2, electrons in the outermost shell that determine the chemical properties of the element.

Unabbreviated electronic configuration of neutral Iridium

Complete ground state electronic configuration for the Iridium atom, Unabbreviated electronic configuration

1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 4f14 5d7 6s2

Atomic Structure of Iridium

Iridium atomic radius is 180 pm, while it's covalent radius is 137 pm.

Atomic Radius

180 pm (1.8 Å)

Atomic Volume 8.5202570922 cm3
Covalent Radius 137 pm (1.37 Å)
Van der Waals Radius N/A
Neutron Cross Section 425 σa/barns

Atomic Spectrum of Iridium

Atomic Spectrum of Iridium | SchoolMyKids

Iridium Chemical Properties: Iridium Ionization Energies and electron affinity

The electron affinity of Iridium is 151 kJ/mol

Valence 6
Electronegativity 2.2
ElectronAffinity 151 kJ/mol

Ionization Energy of Iridium

Refer to table below for Ionization energies of Iridium

Ionization energy number Enthalpy - kJ/mol
1 880
2 1.6×103

Iridium Physical Properties

Refer to below table for Iridium Physical Properties

Density 22.56 g/cm3
Molar Volume 8.5202570922 cm3

Elastic Properties

Young Modulus 528 GPa
Shear Modulus 210 GPa
Bulk Modulus 320 GPa
Poisson Ratio 0.26

Hardness of Iridium - Tests to Measure of Hardness of Element

Mohs Hardness 6.5 MPa
Vickers Hardness 1760 MPa
Brinell Hardness 1670 MPa

Iridium Electrical Properties

Iridium is Conductor of electricity. Refer to table below for the Electrical properties of Iridium

Electrical Conductivity 2.1×107 S/m
Resistivity 4.7×10-8 m Ω
Superconducting Point 0.11

Iridium Heat and Conduction Properties

Thermal Conductivity 150 W/(m K)
Thermal Expansion 6.4×10-6 K-1

Iridium Magnetic Properties

Magnetic Type Paramagnetic
Curie Point N/A
Mass Magnetic Susceptibility 1.67×10-9
Molar Magnetic Susceptibility 3.21×10-10
Volume Magnetic Susceptibility 3.77e-05

Optical Properties of Iridium

Refractive Index N/A

Acoustic Properties of Iridium

Speed of Sound 4825 m/s

Iridium Thermal Properties - Enthalpies and thermodynamics

Refer to table below for Thermal properties of Iridium

Melting Point 2739 K (2466 °C)
Boiling Point 4701 K (4428 °C)
Critical Temperature N/A
Superconducting Point 0.11

Enthalpies of Iridium

Heat of Fusion 26 kJ/mol
Heat of Vaporization 560 kJ/mol
Heat of Combustion N/A

Iridium Isotopes - Nuclear Properties of Iridium

Isotopes of rhodium. Naturally occurring Iridium has 2 stable isotope - 191Ir, 193Ir.

Isotope Isotope Mass % Abundance T half Decay Mode
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   37.3% Stable N/A
192Ir  
193Ir   62.7% Stable N/A
194Ir  
195Ir  
196Ir  
197Ir  
198Ir  
199Ir  

Regulatory and Health - Health and Safety Parameters and Guidelines

CAS Number CAS7439-88-5
RTECS Number N/A
DOT Hazard Class 4.1
DOT Numbers 3089
EU Number N/A
NFPA Fire Rating N/A
NFPA Hazards N/A
NFPA Health Rating N/A
NFPA Reactivity Rating N/A
Autoignition Point N/A
Flashpoint N/A

Database Search

List of unique identifiers to search the element in various chemical registry databases

Database Identifier number
CAS Number - Chemical Abstracts Service (CAS) CAS7439-88-5
CID Number CID23924
Gmelin Number N/A
NSC Number N/A
RTECS Number N/A

List of Elements
1 H - Hydrogen
2 He - Helium
3 Li - Lithium
4 Be - Beryllium
5 B - Boron
6 C - Carbon
7 N - Nitrogen
8 O - Oxygen
9 F - Fluorine
10 Ne - Neon
11 Na - Sodium
12 Mg - Magnesium
13 Al - Aluminium
14 Si - Silicon
15 P - Phosphorus
16 S - Sulfur
17 Cl - Chlorine
18 Ar - Argon
19 K - Potassium
20 Ca - Calcium
21 Sc - Scandium
22 Ti - Titanium
23 V - Vanadium
24 Cr - Chromium
25 Mn - Manganese
26 Fe - Iron
27 Co - Cobalt
28 Ni - Nickel
29 Cu - Copper
30 Zn - Zinc
31 Ga - Gallium
32 Ge - Germanium
33 As - Arsenic
34 Se - Selenium
35 Br - Bromine
36 Kr - Krypton
37 Rb - Rubidium
38 Sr - Strontium
39 Y - Yttrium
40 Zr - Zirconium
41 Nb - Niobium
42 Mo - Molybdenum
43 Tc - Technetium
44 Ru - Ruthenium
45 Rh - Rhodium
46 Pd - Palladium
47 Ag - Silver
48 Cd - Cadmium
49 In - Indium
50 Sn - Tin
51 Sb - Antimony
52 Te - Tellurium
53 I - Iodine
54 Xe - Xenon
55 Cs - Cesium
56 Ba - Barium
57 La - Lanthanum
58 Ce - Cerium
59 Pr - Praseodymium
60 Nd - Neodymium
61 Pm - Promethium
62 Sm - Samarium
63 Eu - Europium
64 Gd - Gadolinium
65 Tb - Terbium
66 Dy - Dysprosium
67 Ho - Holmium
68 Er - Erbium
69 Tm - Thulium
70 Yb - Ytterbium
71 Lu - Lutetium
72 Hf - Hafnium
73 Ta - Tantalum
74 W - Tungsten
75 Re - Rhenium
76 Os - Osmium
77 Ir - Iridium
78 Pt - Platinum
79 Au - Gold
80 Hg - Mercury
81 Tl - Thallium
82 Pb - Lead
83 Bi - Bismuth
84 Po - Polonium
85 At - Astatine
86 Rn - Radon
87 Fr - Francium
88 Ra - Radium
89 Ac - Actinium
90 Th - Thorium
91 Pa - Protactinium
92 U - Uranium
93 Np - Neptunium
94 Pu - Plutonium
95 Am - Americium
96 Cm - Curium
97 Bk - Berkelium
98 Cf - Californium
99 Es - Einsteinium
100 Fm - Fermium
101 Md - Mendelevium
102 No - Nobelium
103 Lr - Lawrencium
104 Rf - Rutherfordium
105 Db - Dubnium
106 Sg - Seaborgium
107 Bh - Bohrium
108 Hs - Hassium
109 Mt - Meitnerium
110 Ds - Darmstadtium
111 Rg - Roentgenium
112 Cn - Copernicium
113 Nh - Nihonium
114 Fl - Flerovium
115 Mc - Moscovium
116 Lv - Livermorium
117 Ts - Tennessine
118 Og - Oganesson
Metalloid
Nonmetals
Other Nonmetals
Halogens Noble Gas
Metals
Alkali Metals Alkaline Earth Metals
Transition Metals Post-Transition Metals
Lanthanide Actinide