Kemija - 2013./14. ljeto - 12.

${\mathrm{C}\mathrm{l}}^{-}\mathrm{i}{\mathrm{C}\mathrm{a}}^{2+}\backslash mathrm\{Cl\}^\{-\}~\backslash mathrm\{i\}~\; \backslash mathrm\{Ca\}^\{2+\}$

${\mathrm{M}\mathrm{g}}^{2+}\mathrm{i}\mathrm{S}{}^{2-}\backslash mathrm\{Mg\}^\{2+\}\; ~\backslash mathrm\{i\}\; ~\backslash mathrm\{S\}\{\; \}^\{2-\}$

${\mathrm{O}}^{2-}\mathrm{i}{\mathrm{S}}^{2-}\backslash mathrm\{O\}^\{2-\}\; \backslash mathrm\{~i\}~\; \backslash mathrm\{S\}^\{2-\}$

${\mathrm{M}\mathrm{g}}^{2+}\mathrm{i}\mathrm{C}\mathrm{a}{}^{2+}\backslash mathrm\{Mg\}^\{2+\}\; ~\backslash mathrm\{i\}~\backslash mathrm\{Ca\}\{\; \}^\{2+\}$