Mark is seventeen years old and drinks heavily. His father keeps alcohol in the house and is gone most of the time leaving Mark with the opportunity to drink, which he does. Mark is likely to experience and as an adult.

You would do 1500/4 and the answer is 375

The answer is d.potassium

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.