Izakhiwo ze-Molybdenum
| Inombolo ye-athomu | 42 |
| Inombolo ye-CAS | 7439-98-7 |
| Isisindo se-athomu | 95.94 |
| Iphoyinti lokuncibilika | 2620°C |
| Iphuzu elibilayo | 5560°C |
| Ivolumu ye-athomu | 0.0153 nm3 |
| Ukuminyana ku-20 °C | 10.2g/cm³ |
| Isakhiwo sekristalu | cubic egxile emzimbeni |
| I-lattice engaguquki | 0.3147 [nm] |
| Ukuchichima koqweqwe lomhlaba | 1.2 [g/t] |
| Isivinini somsindo | 5400 m/s (at rt)(induku ezacile) |
| Ukunwetshwa kwe-thermal | 4.8 µm/(m·K) (ku-25 °C) |
| I-Thermal conductivity | 138 W/(m·K) |
| Ukumelana nogesi | 53.4 nΩ·m (ku-20 °C) |
| Mohs ubulukhuni | 5.5 |
| Vickers ubulukhuni | 1400-2740Mpa |
| Ukuqina kweBrinell | 1370-2500Mpa |
I-Molybdenum iyikhemikhali enophawu luka-Mo kanye nenombolo ye-athomu engu-42. Igama lisuselwa ku-Neo-Latin molybdaenum, lisuselwa ku-Ancient Greek Μόλυβδος molybdos, okusho umthofu, njengoba ama-ore ayo adidaniswa nensimbi yomthofu. Amaminerali e-molybdenum ayaziwa kuwo wonke umlando, kodwa i-elementi yatholakala (ngomqondo wokuyihlukanisa njengenhlangano entsha kusawoti wamaminerali wezinye izinsimbi) ngo-1778 ngu-Carl Wilhelm Scheele. Insimbi yaqala ukuhlukaniswa ngo-1781 nguPeter Jacob Hjelm.
I-molybdenum ayenzeki ngokwemvelo njengensimbi yamahhala Emhlabeni; itholakala kuphela ezindaweni ezihlukahlukene ze-oxidation kumaminerali. I-elementi yamahhala, insimbi esiliva ene-grey cast, inephuzu lokuncibilika lesithupha eliphakeme kunawo wonke lanoma iyiphi i-elementi. Yakha kalula ama-carbides aqinile, azinzile kuma-alloys, futhi ngenxa yalesi sizathu ukukhiqizwa komhlaba wonke kwe-element (cishe 80%) isetshenziswa kuma-alloys ensimbi, okuhlanganisa ama-alloys aphezulu kanye nama-superalloys.
Izingxube eziningi ze-molybdenum zinokuncibilika okuphansi emanzini, kodwa uma amaminerali ane-molybdenum ethinta umoya-mpilo namanzi, i-ion ye-molybdate MoO2-4 ewumphumela iyancibilika impela. Ngokwezimboni, ama-molybdenum compounds (cishe amaphesenti angu-14 okukhiqizwa komhlaba we-elementi) asetshenziswa ekusetshenzisweni kwengcindezi ephezulu kanye nezinga lokushisa eliphezulu njengama-pigments nama-catalysts.
Ama-enzyme aphethe i-molybdenum ayizisusa ezivame kakhulu zebhaktheriya zokuphula isibopho samakhemikhali ku-nitrogen yamangqamuzana asemkhathini ngesikhathi sokulungiswa kwe-nitrogen yebhayoloji. Okungenani ama-enzyme e-molybdenum angama-50 manje ayaziwa kubhaktheriya, izitshalo, nezilwane, nakuba ama-enzyme e-bacterial kanye ne-cyanobacterial kuphela abandakanyeka ekulungiseni i-nitrogen. Lawa ma-nitrogenases aqukethe i-molybdenum esesimweni esihlukile kwamanye ama-enzyme e-molybdenum, wonke aqukethe i-molybdenum ene-oxidized ngokugcwele ku-molybdenum cofactor. Lawa ma-enzyme ahlukahlukene e-molybdenum cofactor abalulekile ezintweni eziphilayo, futhi i-molybdenum iyingxenye ebalulekile yokuphila kuzo zonke izinto eziphilayo eziphakeme ze-eukaryote, nakuba ingekho kuwo wonke amagciwane.
Izici ezingokomzimba
Ngendlela yayo emsulwa, i-molybdenum iyinsimbi e-silvery-grey enobunzima be-Mohs obungu-5.5, kanye nesisindo se-athomu esijwayelekile esingu-95.95 g/mol. Inephuzu lokuncibilika elingu-2,623 °C (4,753 °F); kwezakhi ezenzeka ngokwemvelo, i-tantalum, i-osmium, i-rhenium, i-tungsten, ne-carbon kuphela enamaphuzu aphezulu okuncibilika. Inelinye lama-coefficients aphansi kakhulu okwanda okushisayo phakathi kwezinsimbi ezisetshenziswa ukuthengisa. Amandla aqinile wezintambo ze-molybdenum akhuphuka cishe izikhathi ezi-3, kusukela cishe ku-10 kuya ku-30 GPa, lapho ububanzi bawo buncipha ukusuka ku-~50-100 nm kuya ku-10 nm.
Izakhiwo zamakhemikhali
I-Molybdenum iyinsimbi yoguquko ene-electronegativity engu-2.16 esikalini sika-Pauling. Akubonakali kusabela ngomoya komoya-mpilo noma amanzi ezingeni lokushisa legumbi. I-oxidation ebuthakathaka ye-molybdenum iqala ku-300 °C (572 °F); i-oxidation ngobuningi kwenzeka emazingeni okushisa angaphezu kuka-600 °C, okuholela ku-molybdenum trioxide. Njengezinsimbi eziningi ezisindayo zoguquko, i-molybdenum ikhombisa ukuthambekela okuncane ukwenza i-cation kusisombululo esinamanzi, nakuba i-Mo3+ cation yaziwa ngaphansi kwezimo ezilawulwa ngokucophelela.
Imikhiqizo Eshisayo ye-Molybdenum
