However, as early as 1907, Rutherford and Thomas Royds had shown that alpha particles, which had a charge of +2, were the nuclei of helium atoms, which had a mass four times that of hydrogen, not two times.
haʊˈɛvɚ, æz ˈɜːli æz nˈaɪntiːnhˈʌndɹɪd sˈɛvən, ɹˈʌðɚfɚd ænd tˈɑːməs ɹˈɔɪdz hæd ʃˈoʊn ðæt ˈælfə pˈɑːɹɾɪkəlz, wˌɪtʃ hæd ɐ tʃˈɑːɹdʒ ʌv plˈʌs tˈuː, wɜː ðə nˈuːklɪi ʌv hˈiːliəm ˈæɾəmz, wˌɪtʃ hæd ɐ mˈæs fˈoːɹ tˈaɪmz ðæt ʌv hˈaɪdɹədʒən, nˌɑːt tˈuː tˈaɪmz.