Periodic Table Element Comparison: Compare Elements - Rhodium vs Iridium
Compare Rhodium and Iridium on the basis of their properties, attributes and periodic table facts. Compare elements on more than 90 properties. All the elements of similar categories show a lot of similarities and differences in their chemical, atomic, physical properties and uses. These similarities and dissimilarities should be known while we study periodic table elements. You can study the detailed comparison between Rhodium vs Iridium with most reliable information about their properties, attributes, facts, uses etc. You can compare Rh vs Ir on more than 90 properties like electronegativity , oxidation state, atomic shells, orbital structure, Electronaffinity, physical states, electrical conductivity and many more. Rhodium and Iridium comparison table on more than 90 properties.
Rhodium and Iridium Comparison
Facts
| Name | Rhodium | Iridium |
|---|---|---|
| Atomic Number | 45 | 77 |
| Atomic Symbol | Rh | Ir |
| Atomic Weight | 102.9055 | 192.217 |
| Phase at STP | Solid | Solid |
| Color | Silver | Silver |
| Metallic Classification | Transition Metal | Transition Metal |
| Group in Periodic Table | group 9 | group 9 |
| Group Name | cobalt family | cobalt family |
| Period in Periodic Table | period 5 | period 6 |
| Block in Periodic Table | d -block | d -block |
| Electronic Configuration | [Kr] 4d8 5s1 | [Xe] 4f14 5d7 6s2 |
| Electronic Shell Structure (Electrons per shell) | 2, 8, 18, 16, 1 | 2, 8, 18, 32, 15, 2 |
| Melting Point | 2237 K | 2739 K |
| Boiling Point | 3968 K | 4701 K |
| CAS Number | CAS7440-16-6 | CAS7439-88-5 |
| Neighborhood Elements | Neighborhood Elements of Rhodium | Neighborhood Elements of Iridium |
History
| Parameter | Rhodium | Iridium |
|---|---|---|
| History | The element Rhodium was discovered by H. Wollaston in year 1804 in United Kingdom. Rhodium derived its name from the Greek rhodos, meaning 'rose coloured'. | The element Iridium was discovered by S. Tennant in year 1803 in France and United Kingdom. Iridium derived its name from Iris, the Greek goddess of the rainbow. |
| Discovery | H. Wollaston (1804) | S. Tennant (1803) |
| Isolated | H. Wollaston (1804) | S. Tennant (1803) |
Presence: Abundance in Nature and Around Us
Parts per billion (ppb) by weight / by atoms (1ppb =10^-7 %)
| Property | Rhodium | Iridium |
|---|---|---|
| Abundance in Universe | 0.6 / 0.007 | 2 / 0.01 |
| Abundance in Sun | 2 / 0.02 | 2 / 0.01 |
| Abundance in Meteorites | 180 / 40 | 550 / 60 |
| Abundance in Earth's Crust | 0.70 / 0.1 | 0.4 / 0.05 |
| Abundance in Oceans | - / - | - / - |
| Abundance in Humans | - / - | - / - |
Crystal Structure and Atomic Structure
| Property | Rhodium | Iridium |
|---|---|---|
| Atomic Volume | 8.2655 cm3/mol | 8.5203 cm3/mol |
| Atomic Radius | 173 pm | 180 pm |
| Covalent Radius | 135 pm | 137 pm |
| Van der Waals Radius | - | - |
Atomic Spectrum - Spectral Lines | ||
| Emission Spectrum |  |  |
| Absorption Spectrum |  |  |
| Lattice Constant | 380.34, 380.34, 380.34 pm | 383.9, 383.9, 383.9 pm |
| Lattice Angle | π/2, π/2, π/2 | π/2, π/2, π/2 |
| Space Group Name | Fm_ 3m | Fm_ 3m |
| Space Group Number | 225 | 225 |
| Crystal Structure | Face Centered Cubic  | Face Centered Cubic |
Atomic and Orbital Properties
| Property | Rhodium | Iridium |
|---|---|---|
| Atomic Number | 45 | 77 |
| Number of Electrons (with no charge) | 45 | 77 |
| Number of Protons | 45 | 77 |
| Mass Number | 102.9055 | 192.217 |
| Number of Neutrons | 58 | 115 |
| Shell structure (Electrons per energy level) | 2, 8, 18, 16, 1 | 2, 8, 18, 32, 15, 2 |
| Electron Configuration | [Kr] 4d8 5s1 | [Xe] 4f14 5d7 6s2 |
| Valence Electrons | 4d8 5s1 | 5d7 6s2 |
| Oxidation State | 3 | 3, 4 |
| Atomic Term Symbol (Quantum Numbers) | 4F9/2 | 4F9/2 |
| Shell structure |  |  |
Isotopes and Nuclear Properties
Rhodium has 1 stable naturally occuring isotopes while Iridium has 2 stable naturally occuring isotopes.
| Parameter | Rhodium | Iridium |
|---|---|---|
| Known Isotopes | 89Rh, 90Rh, 91Rh, 92Rh, 93Rh, 94Rh, 95Rh, 96Rh, 97Rh, 98Rh, 99Rh, 100Rh, 101Rh, 102Rh, 103Rh, 104Rh, 105Rh, 106Rh, 107Rh, 108Rh, 109Rh, 110Rh, 111Rh, 112Rh, 113Rh, 114Rh, 115Rh, 116Rh, 117Rh, 118Rh, 119Rh, 120Rh, 121Rh, 122Rh | 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 |
| Stable Isotopes | Naturally occurring stable isotopes: 103Rh | Naturally occurring stable isotopes: 191Ir, 193Ir |
| Neutron Cross Section | 145 | 425 |
| Neutron Mass Absorption | 0.063 | 0.08 |
Chemical Properties: Ionization Energies and electron affinity
| Property | Rhodium | Iridium |
|---|---|---|
| Valence or Valency | 6 | 6 |
| Electronegativity | 2.28 Pauling Scale | 2.2 Pauling Scale |
| Electron Affinity | 109.7 kJ/mol | 151 kJ/mol |
| Ionization Energies | 1st: 719.7 kJ/mol 2nd: 1740 kJ/mol 3rd: 2997 kJ/mol | 1st: 880 kJ/mol 2nd: 1600 kJ/mol |
Physical Properties
| Property | Rhodium | Iridium |
|---|---|---|
| Density | 12.45 g/cm3 | 22.56 g/cm3 |
| Molar Volume | 8.2655 cm3/mol | 8.5203 cm3/mol |
Elastic Properties | ||
| Young Modulus | 275 | 528 |
| Shear Modulus | 150 GPa | 210 GPa |
| Bulk Modulus | 380 GPa | 320 GPa |
| Poisson Ratio | 0.26 | 0.26 |
Hardness - Tests to Measure of Hardness of Element | ||
| Mohs Hardness | 6 MPa | 6.5 MPa |
| Vickers Hardness | 1246 MPa | 1760 MPa |
| Brinell Hardness | 1100 MPa | 1670 MPa |
Electrical Properties | ||
| Electrical Conductivity | 23000000 S/m | 21000000 S/m |
| Resistivity | 4.3e-8 m Ω | 4.7e-8 m Ω |
| Superconducting Point | - | 0.11 |
Heat and Conduction Properties | ||
| Thermal Conductivity | 150 W/(m K) | 150 W/(m K) |
| Thermal Expansion | 0.0000082 /K | 0.0000064 /K |
Magnetic Properties | ||
| Magnetic Type | Paramagnetic | Paramagnetic |
| Curie Point | - | - |
| Mass Magnetic Susceptibility | 1.36e-8 m3/kg | 1.67e-9 m3/kg |
| Molar Magnetic Susceptibility | 1.4e-9 m3/mol | 3.21e-10 m3/mol |
| Volume Magnetic Susceptibility | 0.0001693 | 0.0000377 |
Optical Properties | ||
| Refractive Index | - | - |
Acoustic Properties | ||
| Speed of Sound | 4700 m/s | 4825 m/s |
Thermal Properties - Enthalpies and thermodynamics
| Property | Rhodium | Iridium |
|---|---|---|
| Melting Point | 2237 K | 2739 K |
| Boiling Point | 3968 K | 4701 K |
| Critical Temperature | - | - |
| Superconducting Point | - | 0.11 |
Enthalpies | ||
| Heat of Fusion | 21.7 kJ/mol | 26 kJ/mol |
| Heat of Vaporization | 495 kJ/mol | 560 kJ/mol |
| Heat of Combustion | - | - |
Regulatory and Health - Health and Safety Parameters and Guidelines
| Parameter | Rhodium | Iridium |
|---|---|---|
| CAS Number | CAS7440-16-6 | CAS7439-88-5 |
| RTECS Number | RTECSVI9069000 | - |
| DOT Hazard Class | 4.1 | 4.1 |
| DOT Numbers | 3089 | 3089 |
| EU Number | - | - |
| NFPA Fire Rating | - | - |
| NFPA Health Rating | - | - |
| NFPA Reactivity Rating | - | - |
| NFPA Hazards | - | - |
| AutoIgnition Point | - | - |
| Flashpoint | - | - |
Compare With Other Elements
Compare Rhodium and Iridium with other elements of the periodic table.