The heavier alkali metals react more vigorously than the lighter ones; for example, when dropped into water, caesium produces a larger explosion than potassium if the same number of moles of each metal is used.
ðə hˈɛviɚɹ ˈælkəlˌaɪ mˈɛɾəlz ɹɪˈækt mˈoːɹ vˈɪɡɚɹəsli ðɐn ðə lˈaɪɾɚ wˌʌnz; fɔːɹ ɛɡzˈæmpəl, wˌɛn dɹˈɑːpt ˌɪntʊ wˈɔːɾɚ, sˈiːsiəm pɹədˈuːsᵻz ɐ lˈɑːɹdʒɚɹ ɛksplˈoʊʒən ðɐn pətˈæsiəm ɪf ðə sˈeɪm nˈʌmbɚɹ ʌv mˈoʊlz ʌv ˈiːtʃ mˈɛɾəl ɪz jˈuːzd.