They react aggressively with the halogens to form the alkali metal halides, which are white ionic crystalline compounds that are all soluble in water except lithium fluoride (Li F).
ðeɪ ɹɪˈækt ɐɡɹˈɛsɪvli wɪððə hˈælədʒənz tə fˈɔːɹm ðɪ ˈælkəlˌaɪ mˈɛɾəl hˈælaɪdz, wˌɪtʃ ɑːɹ wˈaɪt aɪˈɑːnɪk kɹˈɪstɐlˌaɪn kˈɑːmpaʊndz ðæt ɑːɹ ˈɔːl sˈɑːljuːbəl ɪn wˈɔːɾɚɹ ɛksˈɛpt lˈɪθiəm flˈʊɹɹaɪd lˈaɪ ˈɛf.