The chemical symbol for Iridium is Ir and its atomic number is 77.
We find it listed in the periodic table in Group 9 and 6 period and block d.
The Iridium belongs to the family of transition metals such as for example the Silver, the Bohrium, cadmium, ...
This element is stable.
Iridium as a name came from the latin word iridos which means rainbow.
Atomic number (Z) 77
Group, block group 9, d-block
Period: period 6
Element category: transition metal
Standard atomic weight (±) (Ar) 192.217(3)
Electron configuration [Xe] 4f14 5d7 6s2
per shell: 2, 8, 18, 32, 15, 2
Physical properties
Phase: solid
Melting point: 2719 K (2446 °C, 4435 °F)
Boiling point: 4403 K (4130 °C, 7466 °F)
Density near r.t. : 22.56 g/cm3
when liquid, at m.p. 19 g/cm3
Heat of fusion: 41.12 kJ/mol
Heat of vaporization: 564 kJ/mol
Molar heat capacity: 25.10 J/(mol·K)
Atomic properties
Oxidation states: −3, −1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9
Electronegativity: Pauling scale: 2.20
Ionization energies 1st: 880 kJ/mol
2nd: 1600 kJ/mol
Atomic radius empirical: 136 pm
Covalent radius: 141±6 pm
Element Crystal structure: face-centered cubic
Speed of sound thin rod: 4825 m/s (at 20 °C)
Thermal expansion: 6.4 µm/(m·K)
Thermal conductivity: 147 W/(m·K)
Electrical resistivity: 47.1 nΩ·m (at 20 °C)
Magnetic ordering: paramagnetic
Young's modulus: 528 GPa
Shear modulus : 210 GPa
Bulk modulus: 320 GPa
Poisson ratio: 0.26
Mohs hardness: 6.5
Vickers hardness: 1760–2200 MPa
Brinell hardness: 1670 MPa
CAS Number: 7439-88-5