Iron-59 has a half-life of 44 days. Assume you started with 24 mg of iron-59 and 132 days, which is equivalent to 3 half-lives, has passed. How much iron-59 remains?

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.

They make up examples of physical properties