1. Ammonium   CO3   NH4   I   Cl   Hint Half-n-half Clue   2. Hydroxide   HCO3   OH   Cl   I   Half-n-half Clue   3. Carbonate   O   CO3   S   SO3   Half-n-half Clue   4. Bisulfite or Hydrogen sulfite   HSO3   SO4   HSO4   O   Half-n-half Clue   5. Bisulfate or Hydrogen sulfate   I   S   PO4   HSO4   Half-n-half Clue   6. Sulfide   SO4   O   S   SO3   Half-n-half Clue   7. Chloride   HCO3   O   Cl   I   Half-n-half Clue