What physical or chemical properties would identify a salt as containing a transition metal ion?

Many transition metal ions(e.g. in soluble salt solutions) give colored hydroxide precipitates when mixed with aqueous sodium hydroxide solution. However zinc ions give a white hydroxide precipitate. These reactions can be used to help identify transition metal ions in solution.

You would be correct, boiling water does disinfect contamination.    the property of disinfecting means to kill  germs, bacteria and other pathogens or contamination  that might cause an infection or cause a person to become sickly. a couple methods of disinfecting are using soap, other cleaning supplies or by simply "boiling" the contaminate.  the reason why boiling water disinfects certain attributes is because some cells cannot survive the heat and pressure.