Umjikelo oksijini endalweni

Ngokusemthethweni azinakanwa-1774, lo yemichiza IsiNgesi Dzhozefom Pristli oksijini (O2) iye yavulwa. Ngenxa ukuhlola okwenziwa ngesitya evaliweyo mercury oxide, phantsi kwempembelelo kwelanga lens ngqo waba ukwanda yayo: 2HgO → O2 ↑ + 2Hg. Le nto sukube lubonakala ngokuba ukuxinana kwi kweemeko eziqhelekileyo 0.00142897 g / cm³, umthamo izinyo ka-14,0 cm³ / igala, indawo ukunyibilika thabatha 218,2 ° C kunye nobushushu elibilayo thabatha 182,81 ° C. mass izinyo ilingana 15,9994 g / Mol. Uphawu eziphambili ioksijini - kukuba layo ukuba oxidize izinto ezahlukeneyo. Njengoko i esebenzayo non-metal, O2 idityaniswe yonke isinyithi kunye nokusekwa oxides ezisisiseko kunye amphoteric, kwakunye nazo zonke non-iintsimbi (ngaphandle halogen) ukuze ufumane oxides acid okanye nesoleobrazuyuschie.

Oksijini ifakiwe ngaphezu kwewaka izinto, njengokuba yeyona ixhaphakileyo i element imichiza ehlabathini. Yena lilungu iikhompawundi ezahlukeneyo chemical (kukho engaphezu kwewaka elinamakhulu amahlanu). Umxholo esiluqilima kuqweqwe O2 komhlaba ilingana 47,4%. In zolwandle kunye namanzi entsha isabelo yalo akhawunti zikarhulumente yento edityanisiweyo ye-88.8% ngokobunzima. Xa mpilo sikwimo simahla, nto ilingana umthamo iqhezu malunga-21%, kunye nobunzima - 23.1%. Lo abakhoyo ebalulekileyo organic izinto ezisegumbini zonke iseli eziphilayo. Xa volume, apho anabo-25% ne-65% ngokobunzima. Umjikelo oksijini kwindalo ngenxa umsebenzi wayo imichiza.

Umjikelo yi uthotho utshintsho wenkqu, ngenxa apho ubuyela njengesiqalo, kwaye ephinda indlela yonke. Oxygen biogeochemical kumjikelo motion. Ngenxa udlula O2 zasemanzini udibaniso zonke eziphilayo (umhlaba onokuphila, okanye ummandla ubomi on Earth) kunye abiotic (lithosfere, umoya kunye kwehayidrosfere) bume. Umjikelo oxygen ichaza intshukumo yayo kwehayidrosfere (ubunzima yamanzi ibekwe phantsi komhlaba kwaye ngaphezu komhlaba), emoyeni (umoya) kwi onokuphila (sum kwihlabathi zonke eziphilayo) kunye lithosfere (uqweqwe). Ukutyeshelwa kwalo mjikelo kwi kwehayidrosfere kunokukhokelela hypoxic (O2 ephantsi) kwiinkalo amachibi ezinkulu neelwandle. Eyona nto iphambili okuqhuba lo photosynthesis.

Iinkqubo uhlumo lwendalo (ecosystem) ezininzi imijikelo biogeochemical, esebenza ukwakhiwa kwawo. Umzekelo, umjikelo wamanzi, yomjikelo ka-oksijini, ukujikeleziswa we nitrogen, carbon, njl Zonke izinto yamachiza umkhondo, eyinxenye ye mijikelo biogeochemical. Lukwa yinxalenye eziphilayo, kodwa ukuhamba ngapha kwendalo esingqongileyo abiotic. Oku amanzi (kwehayidrosfere), kuqweqwe lomhlaba (i lithosfere) kunye emoyeni (umoya). eziphilayo balizalise Iqokobhe Umhlaba ebizwa ngokuba umhlaba onokuphila. Zonke izondlo ezifana ne-carbon, initrogen, ioksijini, iphosphate kunye isalfure, ukuba zisetyenziswa kwaye ziyinxalenye yenkqubo evaliweyo, ngoko ke irisayikilishiweyo kwaye ubelahlekile lomelezwe rhoqo, ezifana kwinkqubo evulekileyo.

Ichibi inkulu O2 (99,5%), lo amaxolo kunye nomhlaba yokwaleka, apho ikhoyo nokubakho kwi silicate kunye oxide izimbiwa. Umjikelo oxygen lingenwe kuphela inxalenye encinane ngohlobo free O2 kwi onokuphila (0.01%), kunye nomoya (0.36%). Lo mthombo uphambili O2 esesibhakabhakeni photosynthesis free. Products yalo izinto eziphilayo kunye mpilo wabumba ukusuka icarbon dioxide kunye namanzi: 6CO2 + 6H2O + amandla → C6H12O6 + 6O2.

Kuba umjikelo ioksijini umhlaba onokuphila ukuphendula izityalo ilizwe, izilwanyana kunye neelwandle. icyanobacteria zaselwandle Tiny (ulwelwe blue-eluhlaza) Prochlorococcus, ubukhulu 0.6 microns, esafunyanwa kunyaka 1986. Bona akhawunti ukuba ngaphezu kwesiqingatha imveliso zefotosinthesis kulwandle oluvulekileyo. Omnye umthombo ioksijini ezikhoyo esesibhakabhakeni lo mkhuba photolysis (basabela yemichiza ebangelwe sisenzo ziluhlaza). Ngenxa wamanzi uwabonisa kunye oxide ke inqanyulwe zibe atom abasemthethweni, hydrogen (H) kunye nitrogen (N) isithuba eso, yaye O2 kwi-atmosfera: 2H2O + amandla → 4H + O2 kunye 2N2O + amandla → 4N + O2. ioksijini uwabonisa kuyaphela eziphilayo simahla kwiinkqubo bokuphefumla ukubola. Lithosfere usebenzisa free O2 ngenxa imichiza yemozulu kunye umphezulu ngayo. Ngokomzekelo, kubhaliwe siphele ukuyilwa of oxides yentsimbi (irusi): 4FeO + O2 → 2Fe2O3 okanye ezinye oxides lwesinyithi kunye nonmetals.

Umjikelo mpilo lukwaquka ndzhendzheleko phakathi lithosfere umhlaba onokuphila. eziphilayo zaselwandle umhlaba onokuphila akhonze njengemithombo calcium carbonate (CaCO3), nto leyo osisityebi O2. Xa umzimba uyafa, iqokobhe layo lingenisiwe nzulu emazantsi olwandle apho kukho ixesha elide ukwakha lekalika (intlenga uqweqwe). iinkqubo yemozulu luqaliswe biosphere kwakhona ukucatshulwa ioksijini simahla lithosfere. Izityalo nezilwanyana wabuyisa nezakhi yodaka ukukhululwa oksijini.