What is the oxidation number of Cr in `Cr_(2)O_(7)^(2-)` ?

Explanation

`Cr_(2) O_(7)^(2-)`
` {:(2 x + 7 (-2) = - 2 ) , (" " 2 x - 14 = - 2) ,(" " x = + 6 ):}`
`:. ` The oxidation number of Cr in `Cr_(2) O_(7)^(2-) ` is + 6