MOLEKULA

MOLEKULA (az lot. moles — massa), zarrachai khurdtarini modda, ki shomili khosiyati khimiyavii on meboshad. Molekula az atomhoi yakkhela (dar moddahoi sodda) va gunogun (dar moddahoi murakkab) iborat ast. shumorai atomho dar Molekula gunogun buda, az 2 (mas., dar 02) to yakchand hazor (mas., dar safedaho, polimerho va g.) meshavad; Molekulai gazhoi inerti yakatomaand. Tarkibi sifati va miqdorii Molekularo bo formulai khimiyavii modda, tartibi bandhoi atomho va mohiyati valenti onro bo formulai strukturi ifoda menamoyand. Shakl va andozai Molekula ba darozii bandhoi bayni atomho va kunji bayni onho (kunjhoi valenti) vobasta ast. Andozai Molekula 10-10—10—7 m, energiyai bandi atoho dar Molekula 107—10* ch/kmol meshavad. Mafhumi Molekularo yakumin bor dar asri 17 Gasendi ba khimiya dokhil karda boshad ham, dar asri 18 M. V. Lomonosov ba mafhumi Molekula («korpuskula») mazmuni saheh doda, dar asosi on yak qator hodisahoro manidod kard. Qonuniyathoi asosii sokhti Molekula dar natijai tadqiqoti reaksiyahoi khimiyavi, sintezu tahlili payvasthoi khimiyavi va istifoda burdani yak qator usulhoi fiziki muayyan karda shudaast. Yake az kharakteristikii muhimi Molekula epergiyai ba atomho dissosiasiya shudani on meboshad. In energiya ba energiyae, ki hangomi az atomho hosilshavii Molekula judo meshavad, barobar ast. Energiyai bayni atomho dar Molekula ustuvorii payvastho, qobiliyati ba reaksiya dokhil shudani moddaho va samti tabadduloti khimiyavii onhoro muayyan mekunad. Polyarizasiya, momenti dipoli va momenti magnitii Molekula khosiyati elektri va magnitii onro ifoda menamoyad. Molekula befosila dar harakat ast. Dar barobar» harakati peshravanda va davrzanandai Molukula harakati dokhilii on (lappishi yadroi atomho, tagiyri holati elektronho) niz ba amal meoyad. Hamai in harakatho dar asosi qonuni mekhanikai kvanti ba vujud meoyand. Hangomi az yak holati kvanti ba holati digarn kvanti guzashtani Molekula yak kvant energiya khorij yo furu burda meshavad. Majmui in guna guzarishho spektrhoi molekulaviro muayyan mekunand. Mafhumi Molekula, omuzishi sokht va khosiyati on dar khimiya, fizika va biologiya ahamiyati kalon dorad. Nig. niz Fizikai molekulavi, Biologiyai molekulavi.