Kemija - 2020. ljeto, 32.

${\mathrm{H}}_2\mathrm{O}\backslash mathrm\{H\}\_\{2\}\; \backslash mathrm\{O\}$

${\mathrm{H}}_3{\mathrm{O}}^{+}\backslash mathrm\{H\}\_\{3\}\; \backslash mathrm\{O\}^\{+\}$

${\mathrm{C}}_2{\mathrm{O}}_4{}^{2-}\backslash mathrm\{C\}\_\{2\}\; \backslash mathrm\{O\}\_\{4\}\{\; \}^\{2-\}$

${\mathrm{H}\mathrm{C}}_2{\mathrm{O}}_4^{-}\backslash mathrm\{HC\}\_\{2\}\; \backslash mathrm\{O\}\_\{4\}^\{-\}$