45 102.910

Rhodium , Rh

Rhodium is a chemical element with the symbol Rh and atomic number 45. A rare silvery-white hard transition metal and a member of the platinum group, rhodium is found in platinum ores and is used in alloys with platinum and as a catalyst. It is usually the most expensive precious metal, though it is sometimes surpassed by rhenium, depending on the market.


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Rh 1-3mm Pieces 99.95% Pure



Rh Rod 6.35mm dia. x 40mm long 99.95% Pure



Rh Rod 6.35mm dia. x 20mm long 99.95% Pure



Rh wire 0.5mm dia. 99.9% Pure



Rhodium Rh,

Purities 99.9% & 99.95%

Rhodium is a hard silvery white and durable metal that has a high reflectance. Rhodium metal does not normally form an oxide, even when heated. Oxygen is absorbed from the atmosphere at the melting point of rhodium, but on solidification the oxygen is released. Rhodium has both a higher melting point and lower density than platinum. It is not attacked by acids: it is completely insoluble in nitric acid and dissolves slightly in aqua regia. A complete dissolution of rhodium in powder form is only obtained in sulfuric acid.

Symbol Rh
Atomic number 45
No. of naturally occurring isotopes 1
Atomic weight 102.9055
Electronic configuration [Kr]4d85s1
Metal radius(12-coordinate)/pm 134
Effective ionic radius(6-coord)/pm V 55
Effective ionic radius(6-coord)/pm IV 60
Effective ionic radius(6-coord)/pm III 66.5
Electronegativity χ 2.2
Density (20°C)/gcm3 12.39
Melting point /°C 1960
Boiling point /°C 3760
ΔHfus/kJmol-1 21.6
ΔHvap/kJmol-1 494
ΔHf(monoatomic gas)/kJmol-1 556(+/-11)
Electrical resistivity (20°C)/u,ohm cm 4.33
Ionization energy/kJmol-1 I 720
Ionization energy/kJmol-1 II 1743
Ionization energy/kJmol-1 III 2997
Temperature (oC) @Vap. Pressure
10-8 Torr 1277
10-6 Torr 1472
10-4 Torr 1707
Electron Beam Good
Crucible ThO2 & Vitreous Graphite
Coil Tungsten
Boat Tungsten
EB Gun preferred