Chromium - ASCII Periodic Table of the Elements

ASCII PERIODIC TABLE OF THE ELEMENTS

  Cr

Relative atomic mass: 51.9961 ± 0.0006

English: Chromium
French: Chrome
Croatian: Krom
German: Chrom
Italian: Cromo
Spanish: Cromo

Atomic number: 24
Group numbers: 6
Period: 4
Standard state (20 °C): solid

Discovery: 1797 Louis-Nicholas Vauquelin (FR)

Chromium was discovered by Louis-Nicholas Vauquelin (FR) in 1797. The origin of the name comes from the Greek word 'chroma' meaning 'colour'. It is a very hard, crystalline, steel-grey metal. The pure metal has a blue-white colour. It is hard, brittle and corrosion-resistant at normal temperatures. Hexavalent compounds are toxic by skin contact. The most important chromium mineral is chromite [Fe,Mg(CrO4)]. It is produced commercially by heating its ore in the presence of silicon or aluminium. Chromium is used to make stainless steel; it gives the colour to rubies and emeralds. Iron-nickel-chromium alloys in various percentages yield an incredible variety of the most important metals in modern technology.

Electronic configuration: [Ar] 3d⁵ 4s¹
Formal oxidation number: +2 +3 +6
Atomic radius: 124.9 pm

Electronegativities: 1.66
Thermal conductivity: 93.7 W/(m K)
Electrical resistivity (20 °C): 12.9 μΩcm

Melting point: 1907 °C
Boiling point: 2671 °C

Heat of fusion: 15.3 kJ/mol
Heat of vaporization: 341.8 kJ/mol
Heat of atomization: 394.51 kJ/mol