Kromium

24
Cr
Kumpulan
6
Kala
4
Blok
d
Proton
Elektron
Neutron
24
24
28
Ciri-Ciri Am
Nombor atom
24
Berat atom
51.9961
Nombor jisim
52
Kategori
Logam peralihan
Warna
Perak
Radioaktif
Tidak
From the Greek word chroma, color
Struktur hablur
Pusat Badan Kubik
Sejarah
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.
Bilangan elektron per petala
2, 8, 13, 1
Konfigurasi elektron
[Ar] 3d5 4s1
Cr
Chromium oxide was used by the Chinese in the Qin dynasty over 2,000 years ago
Ciri-Ciri Fizikal
Fasa
Pepejal
Ketumpatan
7.15 g/cm3
Takat lebur
2180.15 K | 1907 °C | 3464.6 °F
Takat didih
2944.15 K | 2671 °C | 4839.8 °F
Haba pelakuran
20.5 kJ/mol
Haba pengewapan
339 kJ/mol
Muatan haba molar
0.449 J/g·K
Banyak pada kerak bumi
0.014%
Banyak pada alam semesta
0.0015%
High
Kredit imej: 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
Nombor CAS
7440-47-3
PubChem CID Number
23976
Ciri-Ciri Atom
Jejari atom
128 pm
Jejari kovalen
139 pm
Keelektronegatifan
1.66 (Skala Pauling)
Kebolehan mengion
6.7665 eV
Isipadu atom
7.23 cm3/mol
Daya pengaliran terma
0.937 W/cm·K
Keadaan pengoksidaan
-2, -1, 1, 2, 3, 4, 5, 6
Aplikasi
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.
In larger amounts, chromium can be toxic and carcinogenic
Isotop
Isotop stabil
50Cr, 52Cr, 53Cr, 54Cr
Isotop tidak stabil
42Cr, 43Cr, 44Cr, 45Cr, 46Cr, 47Cr, 48Cr, 49Cr, 51Cr, 55Cr, 56Cr, 57Cr, 58Cr, 59Cr, 60Cr, 61Cr, 62Cr, 63Cr, 64Cr, 65Cr, 66Cr, 67Cr