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.
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.