1. Iodide   I   Br   HCO3   SO4   Hint Half-n-half Clue   2. Bromide   Cl   Br   HSO4   NH4   Half-n-half Clue   3. Sulfide   SO4   Cl   CO3   S   Half-n-half Clue   4. Sulfite   SO3   I   SO4   O   Half-n-half Clue   5. Bisulfite or Hydrogen sulfite   SO4   NO3   NH4   HSO3   Half-n-half Clue   6. Bisulfate or Hydrogen sulfate   HSO4   HSO3   SO4   OH   Half-n-half Clue   7. Hydroxide   HSO3   CO3   OH   SO4   Half-n-half Clue