(So named (Greek chroma, "color") in 1797 by N.-L. Vauquelin, French chemist, its discoverer, because of its bright-colored compounds) A grayish-white, crystalline, very hard, metallic chemical element with a high resistance to corrosion. It is used in chromium electroplating, in stainless steel, and in Nichrome.

Symbol: Cr
Atomic number: 24
Atomic weight: 51.9961
Density (at room temperature and pressure): 7.19 g/cc
Melting point: 1,900°C
Boiling point: 2,670°C
Valence: +2, +3, +6
Ground state electron configuration: [Ar]3d54s1

Chromiun
Symbol: Cr
Atomic Number: 24
Boiling Point: 2945 K
Melting Point: 2130 K
Density at 300K: 7.19 g/cm3
Covalent radius: 1.18
Atomic radius: 1.85
Atomic volume: 7.23 cm3/mol
First ionization potental: 6.677 V
Specific heat capacity: 0.449 Jg-1K-1
Thermal conductivity: 93.7 Wm-1K-1
Electrical conductivity: 7.9 106Ω-1m-1
Heat of fusion: 20 kJ/mol
Heat of vaporization: 339.5 kJ/mol
Electronegativity: 1.66 (Pauling's)

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Chro"mi*um (?), n. [NL., fr. Gr. color.] Chem.

A comparatively rare element occurring most abundantly in the mineral chromite. Atomic weight 52.5. Symbol Cr. When isolated it is a hard, brittle, grayish white metal, fusible with difficulty. Its chief commercial importance is for its compounds, as potassium chromate, lead chromate, etc., which are brilliantly colored and are used dyeing and calico printing. Called also chrome.

<-- used as an ingredient in stainless steel, or chrome steel. The yellow pigments are also used in paints, as in painting yellow stripes on macadam higbays. -->

 

© Webster 1913.

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