Properties
| Atomic Mass | 192.217 amu |
| Atomic Number | 77 |
| Melting Point | 2719 K, 2446 C, 4435 F |
| Boiling Point | 4701 K, 4428 C, 8002 F |
| Density | 22.65g/cm3 |
Iridium has a an atomic mass of 192.217amu. Its atomic number is 77 meaning that it has 77 electrons and 77 protons. Knowing that most of the weight of an atom is in the nuclei we can conclude that there 115 neutrons in a Iridium atom. Being a transition metal, Iridium has a high melting point of 2446 degrees C (2719 K, 4435 F) and it also has a high boiling point of 4428 degrees C (4701 K, 8002 F). Iridium is known for having the second highest density of all elements with Osmium as the highest. It is unknown for sure if this is actually true or if Iridium has a higher density. While the measured density of Iridium is slightly lower, a more accurate calculation of density from the space lattice shows a density of 22650 kg/m³ for iridium and 22610 kg/m³ for osmium.
The Structure
The structure of Iridium is a crystal that is a cubic shape. Iridium's electron configuration is 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p66s2 4f14 5d7.
First Energy Level:
2
Second Energy Level: 8
Third Energy Level: 18
Fourth Energy Level: 32
Fifth Energy Level: 15
Sixth Energy Level: 2
Chemical Properties/Reaction Tendencies
Iridium is in the 9th group on the periodic table. It is a white metal that has a slightly yellow color. It is a transitional metal and is considered part of the platinum family. The platinum family is also called the noble metals because just as the noble gasses, they do not react well with other elements (the noble gasses still do not react at all unless forced to while the noble metals don't react compared to the metals). Iridium has a high melting and boiling point and conducts electricity well. It has the highest density of all the elements and it is considered the most corrosive resistant metal meaning it can withstand strong chemicals and not react which goes along with being a noble metal. When heated in air it will quickly react with oxygen. It is a precious metal that is hard and fragile. It has a high elasticity, the second highest metal after osmium.
Compounds with Iridium
Iridium is forced to form many compounds due to its special features that are good for many objects (see Uses) The following compounds are mainly steps to different alloys that we use. They require large amounts of heat to produce and are put together in trying to achieve certain properties like good conductivity or high density for use in different objects.
Fluorides
IrF3
IrF4
IrF6
Ir(F5)4
Chlorides
IrCl2
IrCl3
IrCl4
Bromides
IrBr2
IrBr3
IrBr4
Iodides
IrI2
IrI3
IrI4
Oxides
IrO2 x 2H2O
IrO2
Ir2O3
Sulfides
IrS2
Ir2S3
Selenides
IrSe2
Tellurides
IrTe2
Carbonyls
Ir2(CO)8
Ir4(CO)12
Ir6(CO)16
Complexes
IrCl(CO)3
K3Ir(CN)6
IrCl(CO)(PPh3)2
IrH(CO)(PPh3)3
IrBr3.4H2O
K2IrBr6
Na2IrBr6
IrCl3.3H2O
(NH4)2IrCl6
(NH4)3IrCl6
Na2(IrCl6).6H2O
K2IrCl6
K3Ir(NO2)6
Isotopes
| Natural Abun. (%) |
Atomic Mass |
Half- life |
Decay Mode /Energy (/MeV) |
|
| 166Ir | 165.98546 | 5ms | alpha | |
| 167Ir | 166.98136 | 5ms | alpha | |
| 168Ir | 167.98 | alpha | ||
| 169Ir | 168.9762 | 0.4s | alpha | |
| 170Ir | 169.97497 | 1s | alpha | |
| 171Ir | 170.9717 | 1.5s | alpha | |
| 172Ir | 171.97055 | 2.1s | alpha | |
| 173Ir | 172.96756 | 3s | alpha | |
| 174Ir | 173.96666 | 4s | alpha | |
| 175Ir | 174.96415 | 4.5s | alpha | |
| 176Ir | 175.96348 | 8s | alpha | |
| 177Ir | 176.96135 | 30s | alpha | |
| 178Ir | 177.96105 | 12s | ß+,E.C./ 7.26 | |
| 179Ir | 178.95919 | 4m | E.C./ 4.9 | |
| 180Ir | 179.95926 | 1.5m | E.C./ 6.5 | |
| 181Ir | 180.95764 | 4.9m | ß+,E.C./ 4.2 | |
| 182Ir | 181.95797 | 15m | ß+/ 5.6 E.C. |
|
| 183Ir | 182.95671 | 57m | ß+,E.C./ 3.4 | |
| 184Ir | 183.95756 | 3h | ß+/ 4.7 E.C. |
|
| 185Ir | 184.95673 | 14h | ß+/ 2.6 E.C. |
|
| 186mIr | 1.7h | E.C. | ||
| 186Ir | 185.957943 | 15.7h | E.C./ 3.83 ß+ |
|
| 187Ir | 186.95735 | 10.5h | E.C./ 1.5 | |
| 188Ir | 187.95883 | 1.72d | ß+/ 2.81 E.C. |
|
| 189Ir | 188.958712 | 13.2d | E.C./ 0.53 | |
| 190mIr | 3.2h | ß+,E.C.,I.T. | ||
| 190mIr | 1.2h | I.T./ 0.0263 | ||
| 190Ir | 11.8d | E.C./ 2 | ||
| 191mIr | 4.93s | I.T./ 0.1714 | ||
| 191Ir | 37.5 % | 190.960584 | ||
| 192mIr | 241y | I.T./ 0.161 | ||
| 192mIr | 1.44m | I.T./ 0.058 | ||
| 192Ir | 191.96258 | 73.83d | ß-/ 1.46 | |
| 193mIr | 10.53d | I.T./ 0.0802 | ||
| 193Ir | 62.7 % | 192.962917 | ||
| 194mIr | 170d | ß- | ||
| 194Ir | 193.965069 | 19.3h | ß-/ 2.248 | |
| 195mIr | 3.9h | ß- | ||
| 195Ir | 194.965966 | 2.8h | ß-/ 1.121 | |
| 196mIr | 1.4h | ß- | ||
| 196Ir | 195.96837 | 52s | ß-/ 3.21 | |
| 197mIr | 8.9m | ß-,I.T. | ||
| 197Ir | 196.969629 | 5.8m | ß-/ 2.15 | |
| 198Ir | 197.97216 | 8s | ß-/ 4.1 |