Therefore, the only factor which affects the atomic radius of the alkali metals is the number of electron shells.
ðˈɛɹfoːɹ, ðɪ ˈoʊnli fˈæktɚ wˌɪtʃ ɐfˈɛkts ðɪ ɐtˈɑːmɪk ɹˈeɪdɪəs ʌvðɪ ˈælkəlˌaɪ mˈɛɾəlz ɪz ðə nˈʌmbɚɹ ʌv ᵻlˈɛktɹɑːn ʃˈɛlz.