Covalent bond

A karo na farko da irin wannan ra'ayi kamar yadda wani covalent bond chemists yi magana bayan bude Gilbert Newton Lewis, wanda ya bayyana bond a matsayin socialization na biyu electrons. More kwanan nan karatu sun bayyana kansa covalent bond manufa. A kalma iya dauke covalent sunadarai a matsayin wani ɓangare zarra ikon samar da shaidu da sauran kwayoyin halitta.

Ga wani misali:

Akwai biyu kwayoyin halitta da qananan bambance-bambance a electronegativity (C da CL, C da H). Yawanci, wannan kwayoyin halitta, da tsarin da electron harsashi wanda yake da fasali kusa yadda ya kamata zuwa ga electron harsashi na inert gas.

Lokacin da wadannan yanayi faruwa janye nuclei daga wadannan kwayoyin zarra da electron biyu, kowa a gare su. A wannan yanayin, da electron girgije ba kawai zoba, kamar yadda a ionic bonding. Covalent bond samar da kafaffen haɗi na biyu kwayoyin halitta da gaskiya cewa electron yawa da aka sake rabawa da kuma makamashi da tsarin da aka canza, wanda aka sa ta "karyata" a sarari internuclear daya electron girgijen wani zarra. A mafi m juna overlapping na electron girgije, dangane da aka dauke su more m.

Saboda haka, covalent bond - shi ne ilimi, wanda ya tashi ta hanyar da juna socialization na biyu electrons na zuwa biyu kwayoyin halitta.

Matsayin mai mulkin, da abubuwa da kwayoyin raga da aka kafa ta a covalent bond. Halayyar kwayoyin tsarin ana dab da ruwan a low yanayin zafi, matalauci ruwa solubility da low lantarki watsin. Saboda haka za mu iya cewa dalilin tsarin abubuwa kamar germanium, silicon, chlorine, hydrogen, - wani covalent bond.

Kadarorin da suke da hankula ga irin wannan fili:

1. Jikewa. A karkashin wannan dukiya ne yawanci gane kamar yadda matsakaicin yawan nasabar su iya tsayar da takamaiman kwayoyin halitta. An ƙaddara da adadin jimlar yawan wadanda orbitals a atoms cewa za a hannu a cikin samuwar sinadaran shaidu. A valency na zarra, a daya hannun, za a iya ƙaddara da yawan riga amfani da wannan manufa orbitals.
2. Wayarwa. Dukkanin sunadaran fannonin da nunawa da karfi zai yiwu bond. Matsakaicin ƙarfi aka samu a game da daidaituwa da na sarari fuskantarwa da electron girgije na biyu kwayoyin halitta, kamar yadda suka zoba juna. Bugu da kari, shi ne mai covalent bond dukiya a matsayin fuskantarwa musababin da na sarari tsari na kwayoyin kwayoyin halitta, da cewa shi ne alhakin da "geometrical siffar".
3. Polarizability. A wannan wuri dangane da ra'ayin cewa akwai wani covalent hadin kasu kashi biyu:

• iyakacin duniya, ko da ba-tsakaitã. Sadarwa da wannan irin na iya samar da kawai kwayoyin halitta daban-daban, Ina nufin wadanda electronegativity dabam da yawa, ko a lokuta inda duka electron biyu asymmetrically rarraba.
• nonpolar covalent bond ya auku tsakanin carbon atoms, da electronegativity na wanda shi ne kusan daidai, da kuma electron yawa rarraba ya uniform.

Bugu da kari, akwai wasu gwada yawa halaye na covalent bond:

• Daure makamashi. Wannan siga characterizes iyakacin duniya dangantaka cikin sharuddan da ƙarfi. Karkashin makamashi da ake nufi da adadin zafi da ake bukata don warware connection tsakanin biyu kwayoyin halitta, kazalika da adadin zafi cewa an kasaftawa a su maha? Ar.
• Karkashin bond tsawo da kuma kwayoyin sunadarai nufin da tsawon na line tsakanin nuclei na biyu kwayoyin halitta. Wannan siga characterizes bond ƙarfi ma.
• A dipole lokacin - a yawa wanda characterizes polarity na valence bond.