Emiselwe Valence le imichiza

Ulwazi ubume athom kunye iimolekyuli kwinkulungwane XIX abakwazi achaze isizathu apho inani elithile athom ubuhlobo obuluqilima kunye namanye amasuntswana. Kodwa izimvo zezazinzulu ngaphambi kwexesha labo, kwaye Valence of nangoku efundwayo njengenye imigaqo esisiseko of chemistry.

Ukusuka kwimbali ingcamango "Valence eziqalelo yamachiza"

Outstanding British kwekhulu yemichiza XIX Edvard Franklend eyaqamba ibinzana elithi "unxibelelwano" kwi ukusetyenziswa lwenzululwazi ukuchaza intsebenziswano ye-athom kunye nabanye. Scientific waphawula ukuba ezinye imichiza zenza iikhompawundi kunye nemali efanayo kwezinye atom. Umzekelo, nitrogen uyanamathela athom ezintathu hydrogen molecule ammonia.

NgoMeyi 1852 Frankland wabeka phambili hypothesis ukuba kukho inani elithile iibhondi yemichiza i-atom kungenzeka namanye amasuntswana amancinane zenkqunto. Frankland wasebenzisa ibinzana elithi "amandla kokuxhuma 'ukuchaza oko kamva kubizwa ngokuba Valence. usomachiza British Kusekwe iibhondi imichiza enza atom lweziqalelo ngamnye eyaziwa phakathi kwinkulungwane XIX. Umsebenzi Frankland yaba negalelo elibalulekileyo chemistry noshowo mihla.

uphuhliso imibono

wemithi German FA Kekule ndizilingile 1857 ukuba ikhabhoni chetyrehosnovnym. Xa layo elibona elula - methane - kuvela ngenxa 4 atom hydrogen. Igama elithi "basicity" Inzululwazi wayedla ityumbe iziqalelo iipropati ukudibanisa inani eliqingqiweyo amanye amasuntswana. ERashiya, data kwi isakhiwo mba systematized A. M. Butlerov (1861). Uphuhliso olulolunye kwengcamango gqithisela zathengwa kwiimfundiso utshintsho ngamaxesha athile xa ngeempawu lweziqalelo. Umbhali walo - esinye ebalaseleyo semichiza Russian D. I. Mendeleev. Kwakungqina ukuba Valence na imichiza kwi izakhi, kunye nezinye iipropati zigqitywa indawo leyo bahlala kuyo kule nkqubo ngamaxesha athile.

ukumelwa olubonakalayo lwe Valence nemichiza nimanyane

Ukuba nokwenzeka iimolekyuli ngqondweni - enye yemfaneleko ukuqina kwethiyori Valence. Umfuziselo okokuqala ngo 1860, yaye ukususela 1864 sele usebenzisa ifomula zezakhiwo emele uphawu imichiza circumferential ngaphakathi. Phakathi iisimboli atom dash zibonakaliswe gqithisela, kwaye inani imigca lilingana Valence. Kuloo minyaka efanayo, yenziwa imodeli yokuqala sharosterzhnevye (bona. Ifoto ngasekhohlo). Ngowe-1866 Kekule ecetywayo kwindlela stereochemical-athom kwekhabhoni ngohlobo tetrahedron, into ebandakanyiweyo incwadi yakhe "Organic Chemistry".

Valence of the imichiza, kwaye ukuvela lobudlelane zifundwa G. Lewis, ubani imisebenzi yakhe ngo-1923 emva kokufunyanwa electron. Ngoko wabiza kakubi ityala amasuntswana amancinane, nto leyo eyinxalenye ye kweqokobhe atomic. Kwincwadi yakhe, Lewis wasebenzisa ingongoma apha kumacala omane isimboli yemichiza lokuboniswa electron Valence.

Valency hydrogen neoksijini

Kwangaphambi kokusekwa kwenkqubo ngamaxesha of Valence na imichiza kwi khompawundi yenziwa linokuyithelekisa athom ukuba yaziwa leyo. Hydrogen neoksijini bakhethwa njengereferensi. Enye into chemical otsaleleke mhlawumbi endaweni inani elithile H athom, kunye O.

Ngale ndlela, le iipropati kwesesikweni khompawundi monovalent kunye hydrogen (i valency le element yesibini otyunjwe inani wamaRoma):

• HCl - chloro (I):
• H ₂ O - oksijini (II);
• H. ₃ - nitrogen (III);
• CH ₄ - carbon (IV).

Le oxides ye K ₂ Owu, CO, N _{2 O-3,} Sio _2, SO ₃ kumiselwa Valence lwesinyithi kwaye nonmetals ioksijini, kabini inani athom attachable O. wafumana zilandelayo amaxabiso: K (I), C ( II), N (III) , Si (IV), S (VI).

Indlela ukufumanisa Valence le imichiza

Kukho imithetho ukubunjwa neentambo imichiza kunye ngababini electron eqhelekileyo:

• UMbane oQhelekileyo hydrogen Valence - I.
• Normal oxygen Valence ka - II.
• Beengxenye nonmetals-asezantsi Valence na kumiselwa formula 8 - № iqela apho zibe kwisistim ngamaxesha athile. Higher, ukuba oko kumiselwa inombolo qela.
• Beengxenye icala nomnye valency nani liphezulu linokufikelelwa yi iyafana inani lamaqela kwi lwezakhi.

Ukubekwa Valence eziqalelo eekhemikhali ambaxa olungumgubo lwenziwa usebenzisa algorithm ilandelayo:

1. Bhala ngaphezulu yexabiso iikhemikhali eziqhelekileyo waziwa ngokuba omnye izinto. Hi xikombiso, ku MN ₂ O ₇ oxygen valency ngu II.
2. Bala ixabiso lilonke, ekufuneka liphindaphindwe Valence inani athom le nto amachiza kwi molecule, 2 * 7 = 14.
3. Ukumisela valency le element yesibini, kuba apho ayaziwa. Yahlula ifunyenwe kwi Sec. 2 ixabiso inani athom MN kwi molecule.
4. 14: 2 = 7. Valence oxide manganese kwi liphezulu - VII.

valency esisigxina variable

Valence amaxabiso hydrogen neoksijini ezahlukileyo. Umzekelo, sulphur kwi ambaxa H ₂ S divalent, njengoko ifomula SO ₃ - hexavalent. I-carbon monoxide idityaniswe ioksijini, CO kunye CO ₂ dioxide. Umchiza lokuqala ke Valence ka C II, kunye yesibini - IV. Ixabiso efanayo methane CH _4.

Uninzi izinto musani ukubonisa Valence rhoqo kunye neguquguqukayo, umz, phosphorus, initrogen, nesalfure. Ukukhangelwa unobangela oku kwenza ukuba kwithiyori ubuhlobo umchiza, ingqiqo elektroni iqokobhe Valence, orbitals eziphilayo. Ubukho amaxabiso ezahlukeneyo efanayo iipropati efunyenwe ingcaciso ngesakhiwo-athom kunye iimolekyuli sikhundla.

imibono Modern of Valence

Zonke atom iqanjwa isiqalo entle engqongwe electron kakubi ityala. Iqokobhe engaphandle, leyo zakha, ukuba sidle. Isakhiwo esipheleleyo yeyona uzinze, iqulathe electron 8 (octet). Zemichiza ekwakheni ubuhlobo kunye eqhelekileyo electron ngababini iziphumo e athom imeko ngenkuthalo evumayo.

UMthetho ukuze kwakhiwe zithako ukugqitywa iqokobhe okanye ngokufumana electron bahlehla unpaired - kuxhomekeke ukuba inkqubo kulula ukuba lidlule. Ukuba ingaphezulu ubonelela ukuyilwa ikhemikali iqhina amasuntswana ezimbi abangenawo isibini, izitropu yenza njengoko nje electron unpaired. Ngokutsho concepts mihla, le Valence-athom of imichiza - yeyona ukukwazi ukuvelisa inani elithile iintambo covalent. Umzekelo, kwi molecule, H ₂ S isalfure, emanzini uzuza Valence II (-), kuba atom nganye inxaxheba kukwenziwa izibini ezimbini electron. Umqondiso "-" ibonisa nokutsala kwisibini electron ukuya element electronegative ngakumbi. Ubuncinane electronegative ukuba ixabiso Valence appends "+".

Xa indlela donor-acceptor inxaxheba kwinkqubo ngababini electron isiqalelo elinye kunye nabanye orbitals Valence free.

Ukuxhomekeka le Valence ye isakhiwo atom

Masenze umzekelo carbon ioksijini, njengoko kuxhomekeke kwi isakhiwo kwezinto Valence na imichiza. Periodic Table lunika isishwankathelo iimpawu ezingundoqo atom carbon:

• uphawu chemical - C;
• inombolo into - 6;
• intlawulo yenyukliya - 6;
• protons kwi ngumongo - 6;
• ovela ku - 6, kubandakanywa 4 yangaphandle, 2 zawo ipere, 2 - unpaired.

Ukuba atom carbon Iifomu iibhondi ezimbini CO monoookside, ngoko ukusetyenziswa kwayo inikezelwa 6 kuphela amasuntswana ezimbi. Ukuze sizuze octets ezifunekayo ukuze isi- 4 kwasekwa amasuntswana ezimbi lwangaphandle. Carbon has a Valence of IV (+) e dioxide kunye IV (-) in methane.

inani ngokokuma kwento ioksijini - 8, iqokobhe Valence iqulathe elektroni abathandathu, ababini kubo ukwenza i isibini kwaye bathatha inxaxheba iibhondi imichiza kunye nentsebenziswano kunye namanye atom. UMbane oQhelekileyo oxygen Valence - II (-).

Le valency kunye namachibi karhulumente

Kwiimeko ezininzi iluncedo kakhulu ukuba ukusebenzisa igama elithi "degree of igcwala". Ngoko wabiza ntlawulo atom apho wayeza kufumana ukuba zonke electron baye bafudukela element ziyabophelela, nto leyo iba elektroootritsatelnosti ixabiso eliphezulu (EO). Inani igcwala ukwimo elula zero. Ngu igcwala ngakumbi EO wongezelela isiqalelo '-' phawu, ngaphantsi electronegative - "+". Hi xikombiso, le iintsimbi iqela esingundoqo igcwala yoqobo kunye ion lisola inani elilinganayo kunye umqondiso "+". Kwiimeko ezininzi valency kunye namachibi imo athom kwi ezimbaxa enye ngamanani idibana. Kuphela xa intsebenziswano athom ezininzi electronegative igcwala karhulumente entle, iziqalelo ogama EO ngezantsi - negative. Le mbono "Valence of" ngokufuthi sisebenza kuphela osisiqu esinye isakhiwo eziphilayo.