Pehea e hooholo i ka valence

Ka hua'ōlelo "valence a" he Roma 'ōlelo ( «valēns») ua unuhi like "me ka ikaika." No ka mea manawa mua ka mea, ua oleloia i loko o ke kakahiaka nui 15th kenekulia, akā, kona waiwai ( "lāʻau" a me "extract")ʻaʻohe āna i koe, e hana me kaʻiʻo nō o kēiaʻano. I ka mea hoʻoheheʻe kālā o kēia manaʻo o ka valence mea he kaulana English chemist E. Frankland. He i ka MH 1852 paʻi i kekahi pepa ma i i reinterpreted a pau na theories a me nā mea mahuʻi i ola i ia manawa. Ka mea, ua Eduardom Franklendom hoʻolauna i ka manaʻo o "connective ikaika", a lilo iho la ia i ke kumu o ke ao ana o ka valence, akā, i ka pane i ka nīnau "Pehea e loaʻa i ka valence?" I ia manawa i ole i ua ua kālaiʻia.

Hou kūlana ma ke kūpono 'ana o ke kumumanaʻo Ua pâʻani' o ia ma ka Friedrich August Kekule (1857), Archibald Scott Cooper (1858), A. M. Butlerova (1861), A. av Hoffmann (1865). I ka 1866, F. A. Kekule i loko o kona puke kākau i nā stereochemical kŘkohu Nine Inch nā lātoma me ka kalapona'Ātoma tetrahedral hoʻonohonohoʻia i loko o ka palapala o ka Nails, i lilo akaka no ka puka ana e ho oholo i ka valency, e laʻa me, kalapona.

Paʻa o kēia pähola 'o Nine Inch ka ponaʻana i ka quantum-mechanical e hana, e hoike ana i ka huina huina'ine paʻa i hanaʻia ma ka AaOIeIOUIeXAOAaIN o nā nā'ātoma. Nā'ātoma me unpaired electrons me ka laua i milo, repel a me antiparallel hiki ke ho okumu i ka na huina'ine paʻa. Ke Nine Inch hoopaa i hanaʻia ma waena o nā nā'ātoma like lākou e hoʻokokoke mai, ua hapa 'ia' uhi ia me ka huina'ine ao. E like me ka hopena, ma waena o nā Kora naʻEsau elua ua hana nuʻa o ka uila ka uku ole, a ua o Laielohelohe i ka ikaika hoopiiia nucleus, a hana lātoma. Oia kekahi e hoohalike ai i keʻano papa hana o ka AaOIeIOUIeXAOAaIN o okoa nā'ātoma underlies ka Nine Inch hoopaa kumumanaʻo hana 'ole ka valence hoopaa. A ma hope o nā mea a pau, pehea e ho oholo i ka valence o? He mea pono e hooholo i ka helu o ka mea paa i ka'Ātoma hiki ke hana. I ole ia, e hiki e olelo aku nei ia oe pono e imi i ka helu o ka valence electrons.

Inā mākou e hoʻohana i ka papa'āweʻaweʻa kemika papaʻaina, ia mea maʻalahi ka maopopo pehea e ho oholo i ka valence o ka hehee ai e like me ka helu ana o electrons i loko o ka pā iwi o ka'Ātoma. Ka mea, i kapaʻia valence. A pau o nā kumu i loko o kēlā me kēia hui (hoonohonoho ma kolamu) i loko o ka pā leho i ka hookahi helu o electrons. Ma ka pūʻulu mua o ka oihana mua (H, Li, Na, K a me na mea e ae) he hoʻokahi valence huina'ine. Ka lua (E, mg, Ca, M., a no laila, ma) - elua. A kolu (B, Al, HI, etc.) - no ekolu. I ka ha (C, Si, GE, etc.) - eha valence electrons. I ka lima o ka pūʻulu hehee ai (N, P, E like me, etc.) ka elima valence electrons. Oe ke hoʻomau ma, no ka mea, ua maopopo i ka helu ana o electrons i loko o ka pā iwi o ka huina'ine ao e e like me ka papa'āweʻaweʻa kemika papaʻaina pae helu. Naʻe, ua paa no ka mea mua ekolu pūʻulu o ehiku manawa a me kā lākou mau ōlaʻi a me ka lālani (manawa hoonohonoho ma ka lalani a me ka lalani o ka papaʻaina). Mai ka ha o ka manawa, a me ka ha o ka pūʻulu (e laʻa me, la, Zr, HF, Ku)ʻaoʻao oihana mua o subgroups mea i loko o nā lālani i loko o ka pā iwi o ka helu ana o electrons, 'ē aʻe ma mua o ka pae helu.

Ka manaʻo o "valence o" i keia manawa i undergone mea hou. Aia mea a ianoiyuaa a ole ana hōʻike 'ole kona' epekema ano. Nolaila, i ka hiki e pane i ka nīnau "Pehea e ho oholo i ka valence?" Aole ana hoʻohana no ka methodological hana. Valenceʻana i hana nā'ātoma komo i loko o naoh me ka lātoma e lilo Nine Inch makaukau na kaula paa kapa covalent. No ia mea, valence i ke kāheaʻia wale nō ma ka helu.

No ka laʻana, pehea e ho oholo i ka valence o ka ka sulfur'Ātoma ma ka hui e like me hydrogen sulfide, a sulfuricʻakika. No ka lātoma kahi i ka sulfur'Ātoma ua palapala hoopaa i mau hydrogen nā'ātoma, ka valence o ka luaipele i hydrogen e e like me elua. Ma ka lātoma o sulfuricʻakika kona valence o ka o oxygen mea eono. A me ka mea, i loko o nā hihia a pau o ka valence heluna hapauuku coincides me ka piha waiwai o ka degere o'okesaside o ka ka sulfur'Ātoma i loko o kēia mau nā lātoma. Like H2S lātoma kona degere o ka'okesaside e -2 (mai ka huina'ine pa apŘ o ke kahua ua 'oni iki ma muli o ia ka ka sulfur'Ātoma, i mea oi electronegative). Ma ka lātoma o H2SO4'okesaside helu o ka luaipele nā'ātoma mea like i eono (no ka ua 'oni iki ka huina'ine paʻapū i ka oi electronegative i oxygen'Ātoma).