Symbol	Co
Atomnummer	27
Gruppe	9 (Kobaltgruppe)
Periode	4
Blok	d
Klassifikation	Overgangsmetal

Udseende	Hard lustrous gray metal
Farve	Grå

Antal protoner	27 p+
Antal neutroner	32 n0
Antal elektroner	27 e-

Fra Wikipedia, den gratis encyklopædiKobolt (opkaldt efter bjergtrolden Kobold, som ifølge den folkelige overtro i Tyskland spillede bjergmændene et puds, når udsmeltning af malm slog fejl) er det 27. grundstof i det periodiske system, og har det kemiske symbol Co: Under normale temperatur- og trykforhold optræder dette overgangsmetal som et gråt og sølvskinnende metal, der er hårdere end stål, men samtidig også skrøbeligt og "sprødt". Kobolt "opfører" sig i kemisk henseende omtrent som jern og nikkel; det angribes ikke af atmosfærisk luft.

Fase ved STP	Fast
Massefylde	8.9 g/cm3
Atommasse	58.9332 u

Smeltepunkt	1768 K 1494.85 °C 2722.73 °F
Kogepunkt	3200 K 2926.85 °C 5300.33 °F
Fordampningsvarme	373.3 kJ/mol

Elektronegativitet (Pauling Scale)	1.88
Elektronaffinitet	63.898 kJ/mol
Oxidationstrin	−3, −1, 0, +1, +2, +3, +4, +5 (an amphoteric oxide)
Ioniseringsenergier	760.4 kJ/mol 1648 kJ/mol 3232 kJ/mol 4950 kJ/mol 7670 kJ/mol 9840 kJ/mol 12440 kJ/mol 15230 kJ/mol 17959 kJ/mol 26570 kJ/mol 29400 kJ/mol 32400 kJ/mol 36600 kJ/mol 39700 kJ/mol 42800 kJ/mol 49396 kJ/mol 52737 kJ/mol 134810 kJ/mol 145170 kJ/mol 154700 kJ/mol 167400 kJ/mol 178100 kJ/mol 189300 kJ/mol 204500 kJ/mol 214100 kJ/mol 920870 kJ/mol 966023 kJ/mol

Elektronkonfiguration Kortfattet konfiguration	[Ar] 3d7 4s2
Elektronkonfiguration Fuld konfiguration	1s2 2s2 2p6 3s2 3p6 3d7 4s2
Elektronkonfigurationsdiagram	1s2 2s2 2p6 3s2 3p6 3d7 4s2
Elektroner pr. Skal	2, 8, 15, 2
Valenselektroner	2 or 9
Valency-elektroner	2,3
Bohrs atommodel	Figur: Skaldiagram af Kobolt (Co) atom.
Orbital diagram	1s 2s 2p 3s 3p 3d 4s

Opdagelse og første isolation

Georg Brandt (1735)

Opdagelse af kobolt Cobalt has been used to color glass since the Bronze Age. The word cobalt is derived from the German kobalt, from kobold meaning "goblin", a superstitious term used for the ore of cobalt by miners. The first attempts to smelt those ores for copper or silver failed, yielding simply powder (cobalt(II) oxide) instead. Because the primary ores of cobalt always contain arsenic, smelting the ore oxidized the arsenic into the highly toxic and volatile arsenic oxide, adding to the notoriety of the ore. Swedish chemist Georg Brandt (1694–1768) is credited with discovering cobalt circa 1735, showing it to be a previously unknown element, distinct from bismuth and other traditional metals. Brandt called it a new "semi-metal". He showed that compounds of cobalt metal were the source of the blue color in glass, which previously had been attributed to the bismuth found with cobalt. Cobalt became the first metal to be discovered since the pre-historical period. All other known metals (iron, copper, silver, gold, zinc, mercury, tin, lead and bismuth) had no recorded discoverers.

CAS Number	7440-48-4
ChemSpider ID	94547
EC number	231-158-0
PubChem CID Number	104730