Mg có 3 đồng vị: $^{24}{\rm{Mg}}$, $^{25}{\rm{Mg}}$, $^{26}{\rm{Mg}}$
Cl có 2 đồng vị: $^{35}{\rm{Cl}}$, $^{37}{\rm{Cl}}$
Các CT magie clorua:
$^{35}{\rm{Cl}}^{24}{\rm{Mg}}^{35}{\rm{Cl}}$
$^{37}{\rm{Cl}}^{24}{\rm{Mg}}^{37}{\rm{Cl}}$
$^{35}{\rm{Cl}}^{24}{\rm{Mg}}^{37}{\rm{Cl}}$
$^{35}{\rm{Cl}}^{25}{\rm{Mg}}^{35}{\rm{Cl}}$
$^{37}{\rm{Cl}}^{25}{\rm{Mg}}^{37}{\rm{Cl}}$
$^{35}{\rm{Cl}}^{25}{\rm{Mg}}^{37}{\rm{Cl}}$
$^{35}{\rm{Cl}}^{26}{\rm{Mg}}^{35}{\rm{Cl}}$
$^{37}{\rm{Cl}}^{26}{\rm{Mg}}^{37}{\rm{Cl}}$
$^{35}{\rm{Cl}}^{26}{\rm{Mg}}^{37}{\rm{Cl}}$