In which group is an element that has an outer-level electron configuration consisting of one electron in the d orbital and two
electrons in the ns orbital? *

Density and pressure

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.

Use a magnet to separate iron, evaporate water, i'm not sure how to separate the other two i'm sorry but good luck