Osmium

Symbol	Os
Atomnummer	76
Gruppe	8 (Jerngruppe)
Periode	6
Blok	d
Klassifikation	Overgangsmetal

Udseende	Silvery, blue cast
Farve	Skifergrå

Antal protoner	76 p+
Antal neutroner	114 n0
Antal elektroner	76 e-

Fra Wikipedia, den gratis encyklopædiOsmium (af ὀσμή, osme, græsk for "en lugt") er det 76. grundstof i det periodiske system, og har det kemiske symbol Os: Under normale tryk- og temperaturforhold optræder dette overgangsmetal som et skinnende, let blåligt, og ekstremt tungt og hårdt metal. Osmium udgør sammen med iridium og platin de tunge platinmetaller.

Fase ved STP	Fast
Massefylde	22.59 g/cm3
Atommasse	190.233 u

Smeltepunkt	3306 K 3032.85 °C 5491.13 °F
Kogepunkt	5285 K 5011.85 °C 9053.33 °F
Fordampningsvarme	627.6 kJ/mol

Elektronegativitet (Pauling Scale)	2.2
Elektronaffinitet	103.99 kJ/mol
Oxidationstrin	−4, −2, −1, 0, +1, +2, +3, +4, +5, +6, +7, +8 (a mildly acidic oxide)
Ioniseringsenergier	840 kJ/mol 1600 kJ/mol

Elektronkonfiguration Kortfattet konfiguration	[Xe] 4f14 5d6 6s2
Elektronkonfiguration Fuld konfiguration	1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d6 6s2
Elektronkonfigurationsdiagram	1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d6 6s2
Elektroner pr. Skal	2, 8, 18, 32, 14, 2
Outer shell electrons	2
Valence electrons (incl. d)	8
Valency-elektroner	2,3,4
Bohrs atommodel	Figur: Skaldiagram af Osmium (Os) atom.
Orbital diagram 1s 2s 2p 3s 3p 3d 4s 4p 4d 4f 5s 5p 5d 6s

Opdagelse og første isolation	Smithson Tennant (1803)
Navngivet af	Smithson Tennant
Opdagelse af osmium Osmium was discovered in 1803 by Smithson Tennant and William Hyde Wollaston in London, England. The discovery of osmium is intertwined with that of platinum and the other metals of the platinum group. Platinum reached Europe as platina ("small silver"), first encountered in the late 17th century in silver mines around the Chocó Department, in Colombia. The discovery that this metal was not an alloy, but a distinct new element, was published in 1748. Chemists who studied platinum dissolved it in aqua regia (a mixture of hydrochloric and nitric acids) to create soluble salts. They always observed a small amount of a dark, insoluble residue. Joseph Louis Proust thought that the residue was graphite. Victor Collet-Descotils, Antoine François, comte de Fourcroy, and Louis Nicolas Vauquelin also observed iridium in the black platinum residue in 1803, but did not obtain enough material for further experiments. In 1803, Smithson Tennant analyzed the insoluble residue and concluded that it must contain a new metal. Vauquelin treated the powder alternately with alkali and acids and obtained a volatile new oxide, which he believed was of this new metal—which he named ptene, from the Greek word πτηνος (ptènos) for winged. However, Tennant, who had the advantage of a much larger amount of residue, continued his research and identified two previously undiscovered elements in the black residue, iridium and osmium. He obtained a yellow solution by reactions with sodium hydroxide at red heat. After acidification he was able to distill the formed OsO4. He named it osmium after Greek osme meaning "a smell", because of the ashy and smoky smell of the volatile osmium tetroxide. Discovery of the new elements was documented in a letter to the Royal Society on June 21, 1804.

Original word	osme
Language of origin	Greek
Name source	Egenskaber
Meaning	“Smell”
Naming The name is derived from the Greek 'osme', meaning smell, after the strong odour of osmium tetroxide formed when the metal is exposed to air.

CAS Number	7440-04-2
ChemSpider ID	22379
EC number	231-114-0
PubChem CID Number	23937