Lithium, the lightest of the alkali metals, is the only alkali metal which reacts with nitrogen at standard conditions, and its nitride is the only stable alkali metal nitride.
lˈɪθiəm, ðə lˈaɪɾɪst ʌvðɪ ˈælkəlˌaɪ mˈɛɾəlz, ɪz ðɪ ˈoʊnli ˈælkəlˌaɪ mˈɛɾəl wˌɪtʃ ɹɪˈækts wɪð nˈaɪtɹədʒən æt stˈændɚd kəndˈɪʃənz, ænd ɪts nˈaɪtɹaɪd ɪz ðɪ ˈoʊnli stˈeɪbəl ˈælkəlˌaɪ mˈɛɾəl nˈaɪtɹaɪd.