Symbol	Mo
Atomnummer	42
Gruppe	6 (Kromgruppe)
Periode	5
Blok	d
Klassifikation	Overgangsmetal

Udseende	Gray metallic
Farve	Grå

Antal protoner	42 p+
Antal neutroner	54 n0
Antal elektroner	42 e-

Fra Wikipedia, den gratis encyklopædiMolybdæn (af græsk molybdos, der betyder "bly-agtig") er det 42. grundstof i det periodiske system, og har det kemiske symbol Mo: Under normale temperatur- og trykforhold optræder dette overgangsmetal som et tungt, gråt metal. Rent molybdæn er "sprødt" og er tilbøjeligt til at smuldre hvis man forsøger at bearbejde og formgive materialet. Ligesom wolfram angribes molybdæn ikke af reducerende syrer, end ikke flussyre, til gengæld angribes molybdæn af oxiderende syrer samt smeltede alkalimetaller.

Fase ved STP	Fast
Massefylde	10.28 g/cm3
Atommasse	95.951 u

Smeltepunkt	2896 K 2622.85 °C 4753.13 °F
Kogepunkt	4912 K 4638.85 °C 8381.93 °F
Fordampningsvarme	590.4 kJ/mol

Elektronegativitet (Pauling Scale)	2.16
Elektronaffinitet	72.1 kJ/mol
Oxidationstrin	−4, −2, −1, 0, +1, +2, +3, +4, +5, +6 (a strongly acidic oxide)
Ioniseringsenergier	684.3 kJ/mol 1560 kJ/mol 2618 kJ/mol 4480 kJ/mol 5257 kJ/mol 6640.8 kJ/mol 12125 kJ/mol 13860 kJ/mol 15835 kJ/mol 17980 kJ/mol 20190 kJ/mol 22219 kJ/mol 26930 kJ/mol 29196 kJ/mol 52490 kJ/mol 55000 kJ/mol 61400 kJ/mol 67700 kJ/mol 74000 kJ/mol 80400 kJ/mol 87000 kJ/mol 93400 kJ/mol 98420 kJ/mol 104400 kJ/mol 121900 kJ/mol 127700 kJ/mol 133800 kJ/mol 139800 kJ/mol 148100 kJ/mol 154500 kJ/mol

Elektronkonfiguration Kortfattet konfiguration	[Kr] 4d5 5s1
Elektronkonfiguration Fuld konfiguration	1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d5 5s1
Elektronkonfigurationsdiagram	1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d5 5s1
Elektroner pr. Skal	2, 8, 18, 13, 1
Valenselektroner	6
Valency-elektroner	2,3,4,5,6
Bohrs atommodel	Figur: Skaldiagram af Molybdæn (Mo) atom.
Orbital diagram	1s 2s 2p 3s 3p 3d 4s 4p 4d 5s

Opdaget	Carl Wilhelm Scheele (1778)
Første isolation	Peter Jacob Hjelm (1781)
Opdagelse af molybdæn Molybdenite—the principal ore from which molybdenum is now extracted—was previously known as molybdena. Molybdena was confused with and often utilized as though it were graphite. Like graphite, molybdenite can be used to blacken a surface or as a solid lubricant. Although (reportedly) molybdenum was deliberately alloyed with steel in one 14th-century Japanese sword (mfd. ca. 1330), that art was never employed widely and was later lost. In the West in 1754, Bengt Andersson Qvist examined a sample of molybdenite and determined that it did not contain lead and thus was not galena. By 1778 Swedish chemist Carl Wilhelm Scheele stated firmly that molybdena was (indeed) neither galena nor graphite. Instead, Scheele correctly proposed that molybdena was an ore of a distinct new element, named molybdenum for the mineral in which it resided, and from which it might be isolated. Peter Jacob Hjelm successfully isolated molybdenum using carbon and linseed oil in 1781.

CAS Number	7439-98-7
ChemSpider ID	22374
EC number	231-107-2
PubChem CID Number	23932