Group 8 - 10 / VIIIB; Iron - Platinum Group

	The Iron - Platinum Group is often subdivided into the iron group proper (group 8) containing iron (Fe), cobalt (Co) and nickel (Ni), and the platinum group with ruthenium (Ru), rhodium (Rh), palladium (Pd), Osmium (Os), iridium (Ir) and platinum (Pt). Here we treat them in one module.
		Nothing need to be said about the importance of iron. Nickel is not only an important alloy element in steel (in particular in stainless steels) but in the base element for what are called "super-alloys", indispensable materials for high-temperature applications like in jet turbines. Cobalt also has many applications of its own. Iron, nickel and cobalt are are the only elements that are ferromagnetic at reasonable temperatures and thus often found in magnetic (and thus also electric) machinery and products.
		The platinum group elements are all more or less noble metals, rare and expensive. Besides being used in jewelry, platinum is of extreme technical importance as a kind of universal catalyst for all kind of processes. It is part of the exhaust clean-up system of your present car and will be part of the fuel cells that power (perhaps) the cars of the future. Palladium also finds unique and substantial technical uses.
	Table of Basic Data
Name (German) Iron Eisen Cobalt Cobalt Nickel Nickel Ruthenium Ruthenium Rhodium Rhodium Palladium Palladium Osmium Osmium Iridium Iridium Platinum Platin Atomic number 26 27 28 44 45 46 76 77 78 Atomic mass [u ] 55,85 58,93 58,69 101,07 102,91 106,42 190,2 192,22 195,08 Melting point [K] 1808 1768 1726 2583 2239 1825 3318 2683 2045 Melting point [oC] 1535 1495 1453 2310 1966 1552 3045 2410 1772 Melting point [oF] 2795 2723 2647 4190 3625 2825 5513 4370 3221 Boiling point [K] 3023 3143 3005 4173 4000 3413 4300 4403 4100 Density [g/cm3] 7,87 8,89 8,91 12,45 12,41 12,02 22,61 22,65 21,45 Ionization energy [eV] 7,87 7,86 7,64 7,37 7,46 8,34 8,7 9,1 9,0 Electronegativitiy 1,6 1,7 1,8 1,4 1,5 1,4 1,5 1,6 1,4 Atomic radius [pm] 124,1 125,3 124,6 134 134,5 137,6 135 135,7 138 Ionic radius [pm] 67 82 78 77 75 86 67 66 85 Oxidation numbers 6 bis -2 5 bis -1 4 bis -1 8 bis -2 6 bis -1 4 bis 2 8 bis -2 6 bis -1 6 bis 2 Lattice typ Transformation temp. [oC] bcc 1402 fcc 910 bcc fcc 440 hcp fcc hcp fcc fcc hcp fcc fcc ? Lattice constant [Å] (a or c) 2,86 2,51 4,07 3,52 2,70 4,27 3,80 3,88 2,73 4,31 3,83 3,92 Young's - Modul us [GPa] 213 204 202 (432) 379 113 560 528 168 Therm. expansion coefficient a [10-6K-1] 14,0 12,0 12,5 9,8 8,5 11,2 ? 6,6 8,94
		In case of doubt all numbers are for room temperatures
		fcc = face centered cubic; lattice const. = a bcc = body centered cubic sc = simple cubic hp = simple hexagonal hcp = hexagonal close packed; lattice constants a and c. op = simple orthorhombic, monoclinic, triclinic tp = simple tetragonal dia = diamond structure r = trigonal or rhomboedral trigonal

With frame

Glossary

Periodic Table of the Elements

Bravais Lattices and Crystals

Diamond, and other Carbon Specialities

Lattice and Crystal

Units and Constants

© H. Föll (Iron, Steel and Swords script)