Hnyav ions xa mus rau nuclei nrog cov lej loj dua 4, uas yog, ions tom qab helium nucleus ntawm lub rooj zaum (atoms nrog tus lej atomic ntau dua 2 uas tau poob electrons). Xws li carbon 12, neon 22, calcium 45, hlau 56, krypton 84 thiab uranium 238.
