1. Nitrite   NO2   IO4   C2O4   ClO3   Hint Half-n-half Clue   2. Thiosulfate (S2O3)   S2O3   IO   Cr2O7   NO2   Half-n-half Clue   3. Perbromate   S2O3   H2PO4   BrO4   CrO4   Half-n-half Clue   4. Dichromate (Cr2O7)   ClO4   PO3   Cr2O7   C2O4   Half-n-half Clue   5. Periodate   S2O3   IO4   HPO4   SCN   Half-n-half Clue   6. Thiocyanate   IO   IO4   SCN   IO2   Half-n-half Clue   7. Cyanide   BrO3   IO2   ClO4   CN   Half-n-half Clue