Magnesium is a divalent cation, with oxidation number +2, and bromide is a monovalent anion, with oxidation number -1 for each of the two ions. Thus the compound is electrically neutral.
Each of the two sodium atoms in the formula for sodium oxide has an oxidation number of +1, and the oxygen atom has an oxidation number of -2.
I assume you mean the oxidation number of Mn in the permanganate ion , MnO4- The sum of the oxidation numbers is the charge on a polyatomic ion so Mn has an oxidation number of +7 as each O is assigned -2.
Carbonate is CO32- ion and the oxidation numbers are +4 for carbon and -2 for each oxygen.
I believe K2CO3.
Phosphate is PO43- ion. The oxidation numbers are -2 for each O and +5 for P
Each of the two sodium atoms in the formula for sodium oxide has an oxidation number of +1, and the oxygen atom has an oxidation number of -2.
I assume you mean the oxidation number of Mn in the permanganate ion , MnO4- The sum of the oxidation numbers is the charge on a polyatomic ion so Mn has an oxidation number of +7 as each O is assigned -2.
Carbonate is CO32- ion and the oxidation numbers are +4 for carbon and -2 for each oxygen.
I believe K2CO3.
Phosphate is PO43- ion. The oxidation numbers are -2 for each O and +5 for P
This is the thiosulfate ion. Sulfur shows +6 oxidation number.
In the hydronium ion (H3O+), the oxidation number of carbon is +3.
The oxidation number of the ammonium ion is +I.
Whatever the charge on that ion is.
+2 for Be, +4 for C, -2 for each O in BeCO3
-2 for each Oxygen, +7 for Chlorine in ClO4- ion
The oxidation number of the ion is -1. Oxygen atoms have -2 oxidation number each. Nitrogen's oxidation number is +3: 4 covalent bonds with oxygen yields +4 and the central negative charge yields -1.