MOLIBDEN

MOLIBDEN (lot. Molybdaenum), Mo, elementi khimiyavii guruhi VI sistemai davrii Mendeleev; razami at. 42, massai at. 95,94. Soli 1778 khimiki shved K. Sheels kashf va soli1782 digar khimiki shved P. Gelm az Mo03 hosil kardaast. Molibden elementi nodir buda, 1,1 * 10—4% massai qishri Zaminro tashkil medihad. Dar tabiat 7 izotopi sobiti massai atomashon 92, 94—98 va 100-i M. malum ast. Az 15 minerali malumi on muhimtarinash povellit SaMoO*, vulfenit RMo04, molibdat Fe2(Mo04)3. pN20 meboshand.

Molibden metalli khokistarrangi dushvorgudoz buda, t gud. 2620 ± 10° S, t jush. qarib 4800° S va zichiash 10200 kg/m3 (20° S) ast. Dar harorati 600° S to MoOe oksid meshavad; dar 700° S bo bush ob ba reaksiya rafta, MQ02 hosil mekunad. Dar sharoiti mutadil Molibden bo ftor va hangomi tafsonidan bo khlor, bughoi sulfur, nitrogen, karbon va digar nometallho payvast meshavad. Molibden dar kislotai nitrat, shakhsharob, peroksidi gidrogen va dar harorati 80—100° S dar kislotahoi gidrogenkhlorid va sulfat nagz hal meshavad. Molibden dar payvasthoi khimiyaviash 6, 5, 4, 3 va 2-valenta ast. Seoksidi M. (MoOe) kislotahoi sodda (monogidrat N2MoO«, digidrat N2MoO N20), izopolikislotaho (N2M0uO24, H^M06O2H va g.) hosil menamoyad. Namakhoi kislotahoi soddai Molibden molibdatho va namakhoi izopolikislotahoi on polimolibdatho nom dorand. Az galogsipdho va okengalogenidhoi Molibden MoF6, MqCIs beshtar ahamiyatnokand. Molibden va khulayu payvasthoi onro dar sanoat az konsentrathoi standartii molibdendor hosil mekunand. Molibden baroi hosil namudani pulodhoi legironidashuda, dar elektrotokhyanka, tekhnikai aviasioni, kayhoni va yadroi, yak qator payvasthoi on dar istehsoli lok va rangho (mas. ShgMoO*), masolehi molidani (MOSa) mikronuriho va g. istifoda meshavad. Dar rastaniho Molibden biosintezi kislotahoi nukleat va safedaro metezonad va boisi afzudani khlorofill va vitaminho megardad; az norasoii on rastaniho ba kasali duchor meshavand. Miqdori barziyodi Molibden dar organizmi odam mubodilai moddaro vayron karda, boisi paydo shudani bemorii inris megardad.

Ad.: 3elikman A. N., Molibden, M., 1070; Biologicheskaya rol molibdena. M.. 1072.