1. Bicarbonate or Hydrogen carbonate   S   NO3   HCO3   NH4   Hint Half-n-half Clue   2. Sulfate   CO3   SO4   NO3   SO3   Half-n-half Clue   3. Nitrate   NO3   CO3   Br   O   Half-n-half Clue   4. Iodide   NH4   I   OH   S   Half-n-half Clue   5. Oxide   O   NH4   I   CO3   Half-n-half Clue   6. Bisulfite or Hydrogen sulfite   SO4   SO3   HSO3   NO3   Half-n-half Clue   7. Hydroxide   NO3   O   SO3   OH   Half-n-half Clue