Kobalt
27
Co
Golongan
9
Periode
4
Blok
d
Proton
Elektron
Neutron
27
27
32
Sifat Umum
Nomor atom
27
Massa atom
58,933195
Nomor massa
59
Kategori
Logam transisi
Warna
Abu-abu
Radioaktif
Tidak
Dari bahasa Jerman Kobald, goblin atau roh jahat; juga dari bahasa Yunani cobalos
Struktur kristal
Segienam Sederhana
Sejarah
Cobalt compounds have been used for centuries to impart a rich blue color to glass, glazes and ceramics.
The element was first isolated by Swedish chemist George Brandt in 1735.
He showed it was the presence of the element cobalt that caused the blue color in glass, not bismuth as previously thought.
The element was first isolated by Swedish chemist George Brandt in 1735.
He showed it was the presence of the element cobalt that caused the blue color in glass, not bismuth as previously thought.
Elektron per kulit
2, 8, 15, 2
Konfigurasi elektron
[Ar] 3d7 4s2
Supplemental colbalt is essential in sheep's diets to improve the wools quality
Sifat Fisika
Fase
Solid
Kepadatan
8,86 g/cm3
Titik lebur
1768,15 K | 1495 °C | 2723 °F
Titik didih
3200,15 K | 2927 °C | 5300,6 °F
Kalor peleburan
16,2 kJ/mol
Kalor penguapan
375 kJ/mol
Kapasitas kalor molar
0,421 J/g·K
Kelimpahan di kerak bumi
0,003%
Kelimpahan di alam semesta
0,0003%
Kredit Gambar: Wikimedia Commons (Alchemist-hp)
Pure cobalt chips, electrolytically refined, as well as a high purity cobalt cube for comparison
Nomor CAS
7440-48-4
Nomor PubChem CID
104730
Sifat Atom
Jari-jari atom
125 pm
Jari-jari kovalen
126 pm
Elektronegativitas
1,88 (Skala Pauling)
Potensi Ionisasi
7,881 eV
Volume atom
6,7 cm3/mol
Kondusivitas termal
1 W/cm·K
Bilangan oksidasi
-1, 1, 2, 3, 4, 5
Aplikasi
Cobalt is used in the preparation of magnetic, wear-resistant and high-strength alloys.
Cobalt is widely used in batteries and in electroplating.
Radioactive 60Co is used in the treatment of cancer.
A solution of the chloride is used as a sympathetic ink.
Cobalt is widely used in batteries and in electroplating.
Radioactive 60Co is used in the treatment of cancer.
A solution of the chloride is used as a sympathetic ink.
Cobalt and its compounds are considered to be slightly toxic
Isotop
Isotop stabil
59CoIsotop tidak stabil
47Co, 48Co, 49Co, 50Co, 51Co, 52Co, 53Co, 54Co, 55Co, 56Co, 57Co, 58Co, 60Co, 61Co, 62Co, 63Co, 64Co, 65Co, 66Co, 67Co, 68Co, 69Co, 70Co, 71Co, 72Co, 73Co, 74Co, 75Co