Kemija - 2012./13. ljeto - 26.

A. ${\mathrm{N}\mathrm{O}}_2{}^{-}\backslash mathrm\{NO\}\_\{2\}\{\; \}^\{-\}$

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

C. ${\mathrm{H}\mathrm{N}\mathrm{O}}_2\backslash mathrm\{HNO\}\_\{2\}$

D. ${\mathrm{O}\mathrm{H}}^{-}\backslash mathrm\{OH\}^\{-\}$