Lub zog tso tawm thaum av hauv av roj atom ntawm ib qho khoom tau txais hluav taws xob los ua lub monovalent gaseous negative ion yog hu ua electron affinity (Y) ntawm lub ntsiab. Lub xaim hluav taws xob sib xyaw ntawm ib qho khoom sawv cev rau lub zog tawm thaum hluav taws xob tsim hluav taws xob los ua qhov tsis zoo ion; yog tias nws yog tus nqi tsis zoo, nws txhais tau hais tias lub zog yuav tsum tau nqus (kev sib raug zoo lub zog feem ntau yog hlau, thiab nws yog qhov nyuaj rau kev tsim lub zog ion tsis zoo).
Lub xaim hluav taws xob sib xyaw yog qhov ntsuas ntawm qhov oxidation ntawm ib qho khoom. Qhov ntau dua ntawm qhov sib thooj hauv hluav taws xob, qhov ntau dua qhov sib thooj ntawm atom kom tau txais cov khoom siv hluav taws xob, qhov muaj zog ntau dua qhov tsis muaj hlau tsis sib haum ntawm cov khoom sib xws ntawm cov atom, thiab tsawg dua qhov tsis tu ncua ntawm qhov sib cuam tshuam hluav taws xob.
Vim li ntawm cov kev txwv ntawm cov kev mob, tsis muaj txoj kev ntsuas tseeb rau txoj kev xaim hluav taws xob. Cov ntawv hluav taws xob sib txawv ntawm cov ntawv sib txawv muaj ntau yam, thiab nws tsis qhia lub sij hawm hloov pauv. Yog li no, daim ntawv thov ntawm electron sib puag ncig tsis tau tu ncua.