1. Thiosulfate (S2O3)   HPO4   CNO   S2O3   ClO4   Hint Half-n-half Clue   2. Monohydrogen phosphate   H2PO4   HPO4   CrO4   IO4   Half-n-half Clue   3. Nitrite   IO   BrO2   NO2   CNO   Half-n-half Clue   4. Dihydrogen Phosphate   H2PO4   BrO2   ClO2   BrO4   Half-n-half Clue   5. Bromite   CrO4   BrO2   IO3   ClO3   Half-n-half Clue   6. Chromate   ClO2   S2O3   C2H3O2   CrO4   Half-n-half Clue   7. Dichromate (Cr2O7)   Cr2O7   BrO   ClO4   S2O3   Half-n-half Clue