1. Ammonium   NH4   PO4   SO4   SO3   Hint Half-n-half Clue   2. Bicarbonate or Hydrogen carbonate   O   HSO4   HCO3   HSO3   Half-n-half Clue   3. Bisulfite or Hydrogen sulfite   I   HSO3   OH   Cl   Half-n-half Clue   4. Hydroxide   I   HSO4   Br   OH   Half-n-half Clue   5. Phosphate   OH   Cl   S   PO4   Half-n-half Clue   6. Carbonate   O   HSO4   CO3   NH4   Half-n-half Clue   7. Bisulfate or Hydrogen sulfate   HSO4   NO3   HSO3   HCO3   Half-n-half Clue