Ekiyayaano (valency)
Ekiyayaano kiraga kikolwa kya kuyayaana (to yearn for something) . Gakuweebwa Charles Muwanga !! Ekiyayaano mbeera ya kaziba (atomu) okuyayaanira okuviibwako oba okugaba obusannyalazo(electron) kasobole okuba akaggumivu (stable).
Mu essomabuziba, ekiyayaano (valence oba valency) eky’endagakintu(elemnt) kiba kipimo ky’obusobozi bwa atomu emu bw’okwekwasawaza (bonding) ne atomu endala okukola ebitooli eby’ekikemiko (chemical compunds) oba molekyo.
Omulamwa gw’ekiyayaano gwatekebwawo mu kyasa kya 19 era ne gusobola okunnyonnyola obuzimbe bwa molekyo ez’ebiramu n’ebitali biramu.
Okunoonya ekireetera obuziba(atomu) oba molekyo okwegatta oba okwekwasawaza awamu(bonding together) kwaviirako ebigereeso eby’omulembe guno ebya “enkawasowazo ez’enkyusabuziba” (chemical bonding), omuli ebizimbo bya Lewis (1916), ekigereeso ky’enkwasowazo y’ekiyayaano (valence bond) (1927), emiyitiro gya molekyo (molecular orbitals) (1928), ekire ky’ekiyayaano, n’ebigereeso ebirala mu essomabuzime bingi.
“Ekiyayaano” kitegeeza omuwendo gw’obusanyalazo atomu bw’enegabana, bw’eneyingiza oba bw’enegabira akaziizi(atomu) akalala akabulookeera (akabuyayaanira) okusobola okufuna embeera enzigumivu(stable state). Eky’okulabirako kaboni ayayaanira okugabana obusannyalazo 4, magineziyamu ayayaanira okugaba obusannyalzo 2, ate okisigyeni alookeera okufuna obusannyalazo 2
Mu bikyusabuziba ebimu (in some reactions), atomu zitomeggana mu ngeri nti emu eviibwako obusannyalazo bw’egabira endala ebuyingiza. Ekikula ekitondekedwawo kiyitibwa vatomu (ions), vatomu eyo eba egabye obusannyalazo eyitibwa atopo (cation), ekitegeeza nti egabye kyagi eya negatiivu ate yo n’esigaza ey pozitiivu ate eyo eba efunye obusannyalzo n’eyitibwa atone (anion), ekitegeeza nti efunye kyagi eya negatiivu mu kuva kw’obusannyalazo okubaddewo.
Vatomu z’ebyuma zigaba obusannyalazo ne zikola vatomu eza atopo (cations) ate vatomu ez’ebitali byuma ziweebwa obusannyalazo ne zifuna vatomu eya negatiivu eyitibwa vatone (anion). Singa atomu zigabana mu kifo ky’okuyingiza oba okugaba obusannyalzo, ebitooli ebijjawo biyitibwa bya kiyayaano eky’ekigabanyo (covalent), tebibaamu vatomu oba ka tugambe tewabaawo kuva kwa busannyalazo.