Which of the following is a mixed oxide? (A) $\mathrm { Fe } _ { 2 } \mathrm { O } _ { 3 }$ (B) $\mathrm { PbO } _ { 2 }$ (C) [structure] (D) $\mathrm { BaO } _ { 2 }$
Which of the following is a mixed oxide?
(A) $\mathrm { Fe } _ { 2 } \mathrm { O } _ { 3 }$
(B) $\mathrm { PbO } _ { 2 }$
(C) [structure]
(D) $\mathrm { BaO } _ { 2 }$