Alkali hlau xa mus rau 6 lub ntsiab lus hlau ntawm Pawg IA hauv lub rooj sib tham tshwj tsis yog hydrogen (H), uas yog lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs) thiab francium (Fr. ).
Raws li IUPAC, alkali hlau yog nyob rau hauv pawg IA cov ntsiab lus nyob rau hauv lub sij hawm ntawm lub ntsiab lus. Alkali hlau tag nrho muaj ib qho hluav taws xob sab nraud uas yog nyob rau hauv lub orbital, yog li pab pawg no belongs rau thaj tsam ntawm lub sij hawm. Cov khoom siv tshuaj lom neeg ntawm cov hlau alkali qhia pom tseeb homologous tus cwj pwm, uas yog qhov piv txwv zoo tshaj plaws ntawm lub caij nyoog ntawm cov ntsiab lus. Txawm hais tias hydrogen (H) belongs rau Pawg IA, nws cov khoom siv tshuaj muaj zog sib txawv ntawm cov hlau alkali, yog li nws tsis suav tias yog alkali hlau.
