✔ 最佳答案
all elements with variable oxidation states can act as both oxidant and reductant.
eg 1. oxygen:
water H2O (-2);
hydrogen peroxide H2O2 (-1);
oxygen O2, ozone O3 (0),
dioxygenyl hexafluoroplatinate(IV) [O2][PtF6] (+1/2);
oxygen difluoride OF2 (+2)
eg 2. nitrogen:
ammonia NH3 (-3);
hydrazine NH2NH2 (-2);
nitrogen N2 (0);
dinitrogen monoxide N2O (+1);
nitrogen monoxide NO (+2);
nitrous acid HNO2 (+3);
nitrogen dioxide NO2 (+4);
nitric acid HNO3 (+5).
eg 3. chlorine:
chloride Cl(-) (-1);
chlorine Cl2 (0);
sodium hypochlorite (+1);
chlorous acid HClO2 (+3);
chlorine dioxide ClO2 (+4);
chloric acid HClO3 (+5);
perchloric acid HClO4 (+7).
eg 4. manganese:
manganese Mn (0);
manganese(II) sulphate MnSO4 (+2);
manganese(III) sulphate Mn2(SO4)3 (+3);
manganese dioxide MnO2 (+4);
potassium manganate K2MnO4 (+6);
potassium permanganate KMnO4 (+7).
generally, they include group IV, group V, group VI and group VII (except fluorine), as well as transition metals (metals between scandium Sc (#21) and zinc Zn (#30)).
