Kemija - 2009./10. ljeto - 9.

${\mathrm{B}\mathrm{e}\mathrm{F}}_2\backslash mathrm\{BeF\}\_\{2\}$

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

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

${\mathrm{S}\mathrm{O}}_2\backslash mathrm\{SO\}\_\{2\}$