ˈɔːl twˈɛnti stˈeɪbəl ˈælkəlˌaɪ mˈɛɾəl hˈælaɪdz ɑːɹ nˈoʊn; ðɪ ʌnstˈeɪbəl wˈʌnz ɑːɹ nˌɑːt nˈoʊn, wɪððɪ ɛksˈɛpʃən ʌv sˈoʊdiəm ɐstˈæɾaɪd, bɪkˈʌz ʌvðə ɡɹˈeɪt ɪnstəbˈɪlᵻɾi ænd ɹˈɛɹəɾi ʌv ɐstˈætiːn ænd fɹˈænsiəm.
All twenty stable alkali metal halides are known; the unstable ones are not known, with the exception of sodium astatide, because of the great instability and rarity of astatine and francium.