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