The oxidation state for oxygen in this compound is 2-, as it is for most oxygen compounds.
-2 for each O +6 for each Cr
+6 for each Cr -2 for each O
6+
It is a compound, it has no valency. The Cr in it has a valency of +7
The oxidation number of chromium in Cr2O7 is +7. The oxidation number of oxygen is -2, so 7 O atoms times -2 = -14. In order to balance the -14 on the oxygen atom, each chromium atom must have an oxidation number of +7, because 2 Cr atoms times +7 equals +14.
-2 for each O +6 for each Cr
+6 for each Cr -2 for each O
6+
It is a compound, it has no valency. The Cr in it has a valency of +7
The oxidation number of chromium in Cr2O7 is +7. The oxidation number of oxygen is -2, so 7 O atoms times -2 = -14. In order to balance the -14 on the oxygen atom, each chromium atom must have an oxidation number of +7, because 2 Cr atoms times +7 equals +14.
Ru has oxidation number +8, O has oxidation number of -2
oxidation number of S is +6.It oxidize into SO4 ^-2
The overall oxidation number is -2 so the average oxidation number of O is -1.
Oxidation number of chlorine is +7. oxidation number of O is -2.
The oxidation number for H is +1, and the oxidation number for O is -1.
Oxidation number of Si is +4.Oxidation number of O is -2.
Oxidation number of Nb is +4. Oxidation number of O is -2.