Tantal

Tecken	Ta
Atomnummer	73
Grupp	5 (Vanadingruppen)
Period	6
Block	d
Ämnesklass	Övergångsmetall

Utseende	Gray blue
Färg	Grå

Antal protoner	73 p+
Antal neutroner	108 n0
Antal elektroner	73 e-

Från Wikipedia, den fria encyklopedinTantal är ett hårt metalliskt grundämne. På grund av att tantal spontant täcks av ett skyddande oxidskikt angrips materialet ej av syror och används därför bland annat i kemisk apparatur. Denna egenskap har även gjort tantal till ett sedan 1960-talet efterfrågat ämne för tillverkning av högkvalitativa elektrolytkondensatorer, tantalelektrolytkondensatorer, gemenligen i kortform kallade tantalyter. Sådana kondensatorer används i all slags utrustning med elektronik, där krav på små dimensioner motiverar deras höga pris. Tantal upptäcktes år 1802 av svensken Anders Gustav Ekeberg, som namngav den tåliga metallen efter den antika mytologins Tantalos.

Fas vid STP	Fast
Densitet	16.69 g/cm3
Relativ atommassa	180.948 u

Smältpunkt	3290 K 3016.85 °C 5462.33 °F
Kokpunkt	5731 K 5457.85 °C 9856.13 °F
Ångbildningsvärme	737 kJ/mol

Elektronegativitet (Paulingskalan)	1.5
Elektronaffinitet	31 kJ/mol
Oxidationstal	−3, −1, 0, +1, +2, +3, +4, +5 (a mildly acidic oxide)
Jonisationspotential	761 kJ/mol 1500 kJ/mol

Elektronkonfiguration Kortfattad konfiguration	[Xe] 4f14 5d3 6s2
Elektronkonfiguration Full konfiguration	1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d3 6s2
Elektronkonfigurationsdiagram	1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d3 6s2
Elektroner per skal	2, 8, 18, 32, 11, 2
Outer shell electrons	2
Valence electrons (incl. d)	5
Valency-elektroner	5
Bohrs atommodell	Figur: Skaldiagram över Tantal (Ta) atom.
Orbitaldiagram 1s 2s 2p 3s 3p 3d 4s 4p 4d 4f 5s 5p 5d 6s

Upptäckt	Anders Gustaf Ekeberg (1802)
Första isolation	Jean Charles Galissard de Marignac (1864)
Recognized as a distinct element by	Heinrich Rose (1844)
Upptäckten av tantal Tantalum was discovered in Sweden in 1802 by Anders Ekeberg, in two mineral samples – one from Sweden and the other from Finland. One year earlier, Charles Hatchett had discovered columbium (now niobium), and in 1809 the English chemist William Hyde Wollaston compared its oxide, columbite with a density of 5.918 g/cm3, to that of tantalum, tantalite with a density of 7.935 g/cm3. He concluded that the two oxides, despite their difference in measured density, were identical and kept the name tantalum. After Friedrich Wöhler confirmed these results, it was thought that columbium and tantalum were the same element. This conclusion was disputed in 1846 by the German chemist Heinrich Rose, who argued that there were two additional elements in the tantalite sample, and he named them after the children of Tantalus: niobium (from Niobe, the goddess of tears), and pelopium (from Pelops). The supposed element "pelopium" was later identified as a mixture of tantalum and niobium, and it was found that the niobium was identical to the columbium already discovered in 1801 by Hatchett.

Original word	Tantalos
Language of origin	Greek
Name source	Mytologi
Meaning	“Tantalus”
Naming The name is derived from Tantalus of Greek mythology, who was tormented by water and fruit just out of reach, a reference to tantalum's resistance to dissolving in acid.

CAS Number	7440-25-7
ChemSpider ID	22395
EC number	231-135-5
PubChem CID Number	23956