The physical properties of francium are even sketchier because the bulk element has never been observed; hence any data that may be found in the literature are certainly speculative extrapolations.
ðə fˈɪzɪkəl pɹˈɑːpɚɾiz ʌv fɹˈænsiəm ɑːɹ ˈiːvən skˈɛtʃiɚ bɪkˈʌz ðə bˈʌlk ˈɛlɪmənt hɐz nˈɛvɚ bˌɪn əbzˈɜːvd; hˈɛns ˌɛni dˈeɪɾə ðæt mˈeɪ biː fˈaʊnd ɪnðə lˈɪɾɚɹᵻtʃɚɹ ɑːɹ sˈɜːʔn̩li spˈɛkjʊlətˌɪv ɛkstɹˈæpəlˈeɪʃənz.