Kemija - 2024./25. ljeto - 20.

$\mathrm{C}\mathrm{O}\backslash mathrm\{CO\}$

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

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

${\mathrm{C}\mathrm{H}}_4\backslash mathrm\{CH\}\_\{4\}$