Zvivakwa zveMolybdenum
| Atomic nhamba | 42 |
| CAS nhamba | 7439-98-7 |
| Atomic mass | 95.94 |
| Melting point | 2620°C |
| Boiling point | 5560°C |
| Atomic volume | 0.0153 nm3 |
| Density pa20 °C | 10.2g/cm³ |
| Crystal chimiro | body-center cubic |
| Lattice nguva dzose | 0.3147 [nm] |
| Kuwanda mugoko rePasi | 1.2 [g/t] |
| Kumhanya kwenzwi | 5400 m/s (pa rt)(tsvimbo nhete) |
| Kuwedzera kupisa | 4.8 µm/(m·K) (pa25 °C) |
| Thermal conductivity | 138 W/(m·K) |
| Electrical resistivity | 53.4 nΩ·m (pa20 °C) |
| Mohs kuoma | 5.5 |
| Vickers kuoma | 1400-2740Mpa |
| Brinell kuoma | 1370-2500Mpa |
Molybdenum chinhu chemakemikari chine chiratidzo cheMo uye nhamba yeatomu 42. Zita racho rinobva kuNeo-Latin molybdaenum, kubva kuChigiriki Chekare Μόλυβδος molybdos, zvinoreva lead, sezvo ore dzayo dzakavhiringika nematombo emutobvu. Molybdenum zvicherwa zvave zvichizivikanwa munhoroondo yose, asi chinhu chakawanikwa (mupfungwa yekuchisiyanisa sechinhu chitsva kubva kumamineral salt emamwe simbi) muna 1778 naCarl Wilhelm Scheele. Simbi yakatanga kuparadzaniswa muna 1781 naPeter Jacob Hjelm.
Molybdenum haiitike zvakasikwa sesimbi yakasununguka paNyika; inowanikwa chete munzvimbo dzakasiyana-siyana dze oxidation mumaminerari. Chinhu chemahara, simbi ine sirivheri ine grey cast, ine yechitanhatu-yepamusoro-soro yekunyungudika kwechero chinhu. Iyo inokurumidza kuumba yakaoma, yakagadzikana carbides mu alloys, uye nokuda kwechikonzero ichi yakawanda yepasi rose kugadzirwa kwechinhu (inenge 80%) inoshandiswa musimbi alloys, kusanganisira yakakwirira-simba alloys uye superalloys.
Zvizhinji zvemolybdenum zvine kunyungudika kwakaderera mumvura, asi kana molybdenum-inobereka zvicherwa ikasangana neokisijeni nemvura, iyo molybdate ion MoO2-4 inobuda inonyungudika. Indasitiri, molybdenum makomisheni (angangoita gumi nemana muzana epasi rose kugadzirwa kwechinhu) anoshandiswa mukudzvanya-kupisa uye kutonhora kwakanyanya se pigment uye catalysts.
Molybdenum-bearing enzymes ndiwo anonyanya kukonzeresa mabhakitiriya ekupwanya chisungo chemakemikari mumhepo yemuchadenga molecular nitrogen mukugadziriswa kwebiological nitrogen. Anosvika makumi mashanu molybdenum enzymes ave kuzivikanwa mumabhakitiriya, zvidyarwa, uye mhuka, kunyangwe mabhakitiriya uye cyanobacterial enzymes chete anobatanidzwa mukugadzirisa nitrogen. Aya ma nitrogenase ane molybdenum muchimiro chakasiyana nemamwe maenzayimu emolybdenum, ayo ese ane molybdenum yakazara oxidized mu molybdenum cofactor. Aya akasiyana-siyana emolybdenum cofactor enzymes akakosha kune zvipenyu, uye molybdenum chinhu chakakosha pahupenyu muzvisikwa zvese zvepamusoro zveeukaryote, kunyangwe zvisiri mumabhakitiriya ese.
Zvinhu zvemuviri
Muchimiro chayo chakachena, molybdenum isimbi ine silvery-grey nekuoma kweMohs kwe5.5, uye huremu hweatomu hwe 95.95 g/mol. Iine nzvimbo yekunyungudika ye2,623 °C (4,753 °F); yezvinhu zvinongoitika, chete tantalum, osmium, rhenium, tungsten, uye kabhoni zvine mapoinzi ekunyungudika. Iyo ine imwe yeakaderera coefficients yekuwedzera kwekupisa pakati pesimbi dzinoshandiswa kutengeserana. Kusimba kwetambo dzemolybdenum kunowedzera kanenge katatu, kubva pa10 kusvika ku30 GPa, apo dhayamita yavo inoderera kubva ~ 50-100 nm kusvika 10 nm.
Chemical properties
Molybdenum isimbi inoshandura ine electronegativity ye2.16 pachiyero chePauling. Iyo hairatidzike kuita neokisijeni kana mvura patembiricha yekamuri. Kusasimba kwe oxidation ye molybdenum kunotanga pa 300 °C (572 °F); bulk oxidation inoitika patembiricha iri pamusoro pe600 °C, zvichikonzera molybdenum trioxide. Kufanana nesimbi zhinji dzinorema dzekuchinja, molybdenum inoratidza kushomeka kudiki kugadzira cation mune aqueous solution, kunyangwe iyo Mo3+ cation ichizivikanwa pasi pemamiriro akanyatso kudzora.
Zvinopisa Zvigadzirwa zveMolybdenum
