Kemija - 2009./10. ljeto - 1.

${\mathrm{H}}_2{\mathrm{C}\mathrm{O}}_3\backslash mathrm\{H\}\_\{2\}\; \backslash mathrm\{CO\}\_\{3\}$

${\mathrm{H}\mathrm{N}\mathrm{O}}_3\backslash mathrm\{HNO\}\_\{3\}$

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

${\mathrm{N}\mathrm{H}}_3\backslash mathrm\{NH\}\_\{3\}$