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Element 24 - Chromium (Cr) sound

From chroma, or color; discovered 1797. A very bright, silvery metal, it forms compounds valued as pigments for their vivid green, yellow, red, and orange colors. The ruby takes its color from chromium. Besides lustrous chrome plate, its alloys include a number of special hard steels.

Properties

Atomic Number: 24
Atomic Weight: 51.996
Electron Configuration (at ground state): 1s22s22p63s23p63d54s1
Oxidation States (Bold most stable): +2, +3, +6
Boiling Point (K): 2945
Melting Point (K): 2130
Density (at 300K -- g/cm3): 7.19
Atomic Volume (at 300K -- cm3/mol) 7.23
Number of stable isotopes: 4
Mass Number (Bold naturally occurring) -- Half-Life -- Disintigration Type: 51 -- 27.70 days -- orbital electron capture
Covalent Radius (Å): 1.18
Atomic Radius (Å): 1.30
First Ionization Potential (V): 6.766
Electronegativity (Pauling's): 1.66
Specific Heat Capacity (at 300K -- J g-1 K-1): 0.449
Heat of Vaporization (kJ/mol): 339.5
Heat of Fusion (kJ/mol): 20
Electrical Conductivity (at 293K for polycrystalline material -- 106 (ohms)-1 cm-1): 7.9
Thermal Conductivity (at 300K -- W m-1 K-1): 93.7
Crystal Structure: Cubic, body centered
Acid-Base Properties: Very acidic