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Ruthenium
Symbol: Ru
Atomic Number: 44
Atomic Weight: 101.07
Element Classification: Transition Metal
Discovered By: Karl Klaus
Discovery Date: 1844 (Russia)
Name Origin: Latin: Ruthenia (Russia).
Density (g/cc): 12.41
Melting Point (°K): 2583
Boiling Point (°K): 4173
Appearance: Rare, silver-gray, extremely brittle metal
Atomic Radius (pm): 134
Atomic Volume (cc/mol): 8.3
Covalent Radius (pm): 125
Ionic Radius: 67 (+4e)
Specific Heat (@20°C J/g mol): 0.238
Fusion Heat (kJ/mol): (25.5)
Evaporation Heat (kJ/mol): n/a
Thermal Conductivity (@25°C W/m K):
Debye Temperature (°K): n/a
Pauling Negativity Number: 2.2
First Ionizing Energy (kJ/mol): 710.3
Oxidation States: 8, 6, 4, 3, 2, 0, -2
Electronic Configuration: [Kr] 4d7 5s1
Lattice Structure: Hexagonal (HEX)
Lattice Constant (Å): 2.700
Lattice C/A Ratio: 1.584
Mineral Hardness [no units]: 6.5
Brinell Hardness [/MN m-2]: 2160
Note: Ruthenium is a hard, brittle metal that is not too difficult to prepare. Relatively few metallographers work with precious metals,
other than those used in electronic devices.