Kemija - 2012./13. ljeto - 38.

A. ${\mathrm{S}}^{2-}\backslash mathrm\{S\}^\{2-\}$

B. ${\mathrm{S}}_2{}^{2-}\backslash mathrm\{S\}\_\{2\}\{\; \}^\{2-\}$

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

D. ${\mathrm{F}\mathrm{e}}^{2+}\backslash mathrm\{Fe\}^\{2+\}$