Tellur

Symbol	Te
Atomnummer	52
Gruppe	16 (Chalkogener)
Periode	5
Blok	p
Klassifikation	Halvmetal

Udseende	-
Farve	Sølv

Antal protoner	52 p+
Antal neutroner	76 n0
Antal elektroner	52 e-

Fra Wikipedia, den gratis encyklopædiTellur, internationalt tellurium (af latin; tellus for "jord") er det 52. grundstof i det periodiske system, og har det kemiske symbol Te. Under normale temperatur- og trykforhold optræder stoffet som et skinnende hvidt metal; det er "skørt", så det knuses let til et pulver eller granulat.

Fase ved STP	Fast
Massefylde	6.24 g/cm3
Atommasse	127.603 u

Smeltepunkt	722.66 K 449.51 °C 841.118 °F
Kogepunkt	1261 K 987.85 °C 1810.13 °F
Fordampningsvarme	50.63 kJ/mol

Elektronegativitet (Pauling Scale)	2.1
Elektronaffinitet	190.161 kJ/mol
Oxidationstrin	−2, −1, +1, +2, +3, +4, +5, +6 (a mildly acidic oxide)
Ioniseringsenergier	869.3 kJ/mol 1790 kJ/mol 2698 kJ/mol 3610 kJ/mol 5668 kJ/mol 6820 kJ/mol 13200 kJ/mol

Elektronkonfiguration Kortfattet konfiguration	[Kr] 4d10 5s2 5p4
Elektronkonfiguration Fuld konfiguration	1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p4
Elektronkonfigurationsdiagram	1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p4
Elektroner pr. Skal	2, 8, 18, 18, 6
Valenselektroner	6
Valency-elektroner	2,4,6
Bohrs atommodel	Figur: Skaldiagram af Tellur (Te) atom.
Orbital diagram	1s 2s 2p 3s 3p 3d 4s 4p 4d 5s 5p

Opdaget	Franz-Joseph Müller von Reichenstein (1782)
Første isolation	Martin Heinrich Klaproth
Navngivet af	Martin Heinrich Klaproth (1798)
Opdagelse af tellur Tellurium (Latin tellus meaning "earth") was discovered in the 18th century in a gold ore from the mines in Kleinschlatten (today Zlatna), near today's city of Alba Iulia, Romania. In 1782 Franz-Joseph Müller von Reichenstein, who was then serving as the Austrian chief inspector of mines in Transylvania, concluded that the ore did not contain antimony but was bismuth sulfide. The following year, he reported that this was erroneous and that the ore contained mostly gold and an unknown metal very similar to antimony. After a thorough investigation that lasted three years and included more than fifty tests, Müller determined the specific gravity of the mineral and noted that when heated, the new metal gives off a white smoke with a radish-like odor; that it imparts a red color to sulfuric acid; and that when this solution is diluted with water, it has a black precipitate. Nevertheless, he was not able to identify this metal and gave it the names aurum paradoxum (paradoxical gold) and metallum problematicum (problem metal), because it did not exhibit the properties predicted for antimony. In 1789, a Hungarian scientist, Pál Kitaibel, discovered the element independently in an ore from Deutsch-Pilsen that had been regarded as argentiferous molybdenite, but later he gave the credit to Müller. In 1798, it was named by Martin Heinrich Klaproth, who had earlier isolated it from the mineral calaverite.

Original word	tellus
Language of origin	Latin
Name source	Astronomisk objekt
Meaning	“Earth”
Naming The name is derived from the Latin word 'tellus', meaning Earth, chosen to mirror selenium (named after the Moon) which is chemically similar.

CAS Number	13494-80-9
ChemSpider ID	4885717
EC number	236-813-4
PubChem CID Number	6327182