Sei kuona Valencia

Shoko "Valence kuti" mutauro Latin ( «valēns») rinoshandurwa kuti "vane simba." Kokutanga rinotaurwa muna remakore rechi15, asi kukosha kwayo ( "zvinodhaka" kana "mushoma") aiva nechokuita ine dudziro ano. Muvambi pfungwa iyi Valence chinhu akakurumbira kemisiti Chirungu E. Frankland. Iye muna 1852 yakabudiswa pepa iri zvakanga reinterpreted ose dzidziso uye zvekungofungira kuti aivapo panguva iyoyo. Yaiva Eduardom Franklendom vakasuma pfungwa "connective simba", rwakazokura hwaro dzidziso Valence, asi mhinduro yomubvunzo wokuti, "How kuwana Valence?" Panguva iyoyo yakanga isati akagadzira.

Uyezve muchinangwa kukura dzidziso yakanga reDare Friedrich August Kekule (1857), Archibald Scott Cooper (1858), A. M. Butlerova (1861), A. of Hoffmann (1865). Muna 1866, F. A. Kekule mubhuku rake akataura stereochemical wokuenzanisira namakemikari mamorekuru pamwe kabhoni atomu tetrahedral configuration muchimiro vanodhirowa, izvo zvakava pachena sei kuziva valency, semuenzaniso, carbon.

Kunyatsogona ano dzidziso kwemakemikari chokuedza ndiyo quantum-zvokuimba chaitwa, achiratidza kuti yose Erekitironi vaviri inoumbwa kubata kwemaatomu maviri. Maatomu vane unpaired maerekitironi pamwe dzakafanana Muruoko rwake anobata chirukiso, dzinga uye antiparallel vanokwanisa wezvamatongerwe nevakawanda Erekitironi peya. Makemikari chisungo kuumbwa pakati maatomu maviri sezvo vachiswedera, ari zvishoma akazadza Erekitironi makore. Somugumisiro, pakati cores maviri aumbwa arambe achirema pamusoro yemagetsi muripo, izvo mwoyo chokwadi mhosva neerekitironi akaumba Morekuru. Nomufananidzo kwakadaro pamusoro mashandiro ose nekuita kwemaatomu akasiyana irimo makemikari chisungo dzidziso nzira kana Valencia chisungo. Saka pashure zvose, sei kuona Valencia ose? Zvakakodzera kuona uwandu zvisungo kuti atomu zvingaite. Zvikasadaro, unogona kutaura kuti unofanira kuwana nhamba yose Valencia maerekitironi.

Kana tikashandisa periodic table, zviri nyore kunzwisisa sei kuziva Valence ari chinhu maererano nokuwanda maerekitironi kuruvazhe goko ane atomu. Dzinonzi Valencia. Zvose zvinhu nerimwe boka (yakarongwa muzvikamu) kuruvazhe anoshongwa zvakafanana nhamba maerekitironi. In boka zvinhu (H, Li, Na, K nevamwe) wekutanga ane Valencia Erekitironi. Wechipiri (Iva, MG, Ca, Sr, uye zvichingodaro) - maviri. A yechitatu (B, Al, Ga, etc.) - matatu. In wechina (C, Si, Ge, etc.) - mana Valencia maerekitironi. In rechishanu boka chinhu (N, P, sezvo, etc.) nokuda shanu Valencia maerekitironi. Unogona kuramba, nokuti zviri pachena kuti nhamba maerekitironi kuruvazhe goko pamusoro Erekitironi gore achava akaenzana periodic table boka nhamba. Zvisinei, ichi chinobatanidza mapoka okutanga matatu nomwe nguva uye dzavo shamisa uye misara (nguva yakarongwa mumitsara uye mitsara tafura). Sezvo nguva wechina uye boka rechina (semuenzaniso, Ti, Zr, Zvakanaka hf, Ku) divi zvinhu subgroups zviri misara vari rokunze goko mukuwanda maerekitironi, kunze boka nhamba.

Pfungwa yokuti 'Valence kuti "nguva yose iyi kwave kuchiita kuchinja. Pari zvino hakuna kwezvipimo kana nokududzirwa nesayenzi. Naizvozvo, kukwanisa kupindura mubvunzo "sei kuona Valence?" Ko kazhinji kushandiswa methodological zvinangwa. Valence vaifungidzira kugona maatomu achipinda maitiro pamwe Morekuru yokuumba zvisungo nemakemikari inonzi covalent. Saka Valence ringaratidzwa chete nevanhu integer.

Somuenzaniso, sei kuona Valence of sarufa atomu mu yeimwe akadai sehydrogen sulfide, kana sulfuric acid. Nokuti morekuru apo pane sarufa atomu iri waakaita kuti rehydrogen maatomu maviri, ari Valence ari nesurferi kuti rehydrogen vachava akaenzana maviri. In morekuru zviri sulfuric asidhi kwayo Valence reokisijeni ndiyo matanhatu. Uye chokwadi, muna vacho Valence dziwande rinobatana Mhedziso kukosha mwero oxidation of sarufa atomu pachinhu mamorekuru izvi. Sezvo H2S Morekuru kwayo mwero oxidation vachatitaka -2 (kubvira Erekitironi arambe achirema pamusoro inotungamirwa iri zvava nokuda nesarufa atomu, riri kupfuura electronegative). Mune morekuru H2SO4 oxidation nhamba rwesarufa maatomu akaenzana nhanhatu (kubvira Erekitironi arambe achirema iri zvava kupfuura electronegative okisijeni atomu).