Kromo
24
Cr
Grupo
6
Perio
4
Bloko
d
Protonoj
Elektronoj
Neŭtronoj
24
24
28
Ĝeneralaj Propraĵoj
Atoma Nombro
24
Atommaso
51,9961
Amasa Nombro
52
Kategorio
Transirmetaloj
Koloro
Arĝento
Radioaktiva
Ne
De la Greka vorto chroma, koloro
Kristala Strukturo
Korpo Centrita Kubo
Historio
In 1797, Louis Nicolas Vauquelin received samples of crocoite ore.
In 1798, Vauquelin discovered that he could isolate metallic chromium by heating the oxide in a charcoal oven, making him the discoverer of the element.
Vauquelin was also able to detect traces of chromium in precious gemstones, such as ruby or emerald.
In 1798, Vauquelin discovered that he could isolate metallic chromium by heating the oxide in a charcoal oven, making him the discoverer of the element.
Vauquelin was also able to detect traces of chromium in precious gemstones, such as ruby or emerald.
Elektronoj per ŝelo
2, 8, 13, 1
Elektrona Agordo
[Ar] 3d5 4s1
Chromium oxide was used by the Chinese in the Qin dynasty over 2,000 years ago
Fizikaj Propraĵoj
Fazo
Solido
Denso
7,15 g/cm3
Fandpunkto
2180,15 K | 1907 °C | 3464,6 °F
Bolpunkto
2944,15 K | 2671 °C | 4839,8 °F
Varmo de Fuzio
20,5 kJ/mol
Varmo de Vaporiĝo
339 kJ/mol
Specifa Varmo Kapacito
0,449 J/g·K
Krusta Abundo
0,014%
Universa Abundo
0,0015%
Bildaj kreditoj: Wikimedia Commons (Alchemist-hp)
High purity chromium crystals, produced by chemical transport reaction through decomposition of chromium iodides, as well as a high purity chromium cube for comparison
CAS Nombro
7440-47-3
PubChem Kunmetita Identiga Nombro
23976
Atomaj Propraĵoj
Atoma Radiuso
128 pm
Kovalenta Radiuso
139 pm
Elektronegativeco
1,66 (Pauling-skalo)
Potencialo de jonigo
6,7665 eV
Atoma Volumo
7,23 cm3/mol
Termika Kondukto
0,937 W/cm·K
Oksidaj Ŝtatoj
-2, -1, 1, 2, 3, 4, 5, 6
Aplikoj
Chromium is used to harden steel, manufacture stainless steel, and form many useful alloys.
It is mostly used in plating to produce a hard, beautiful surface and to prevent corrosion.
The metal is also widely used as a catalyst.
Chromium compounds are valued as pigments for their vivid green, yellow, red and orange colors.
It is mostly used in plating to produce a hard, beautiful surface and to prevent corrosion.
The metal is also widely used as a catalyst.
Chromium compounds are valued as pigments for their vivid green, yellow, red and orange colors.
In larger amounts, chromium can be toxic and carcinogenic
Izotopoj
Stabilaj Izotopoj
50Cr, 52Cr, 53Cr, 54CrMalstabilaj Isotopoj
42Cr, 43Cr, 44Cr, 45Cr, 46Cr, 47Cr, 48Cr, 49Cr, 51Cr, 55Cr, 56Cr, 57Cr, 58Cr, 59Cr, 60Cr, 61Cr, 62Cr, 63Cr, 64Cr, 65Cr, 66Cr, 67Cr