Kemija - 2021. ljeto, 13.

$\mathrm{M}\mathrm{g}\mathrm{O}\backslash mathrm\{MgO\}$

${\mathrm{A}\mathrm{l}}_2{\mathrm{O}}_3\backslash mathrm\{Al\}\_\{2\}\; \backslash mathrm\{O\}\_\{3\}$

${\mathrm{S}\mathrm{i}\mathrm{O}}_2\backslash mathrm\{SiO\}\_\{2\}$

${\mathrm{S}\mathrm{O}}_3\backslash mathrm\{SO\}\_\{3\}$