ANSWER PLS AND TY. (BTW will give branliest) Use the following equation: 2Mg + O2 → 2MgO

If 20 grams of MgO were produced, and the reaction used 15 g of Mg, how much O2 was used?

B. a graduated substance

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.

The answer for this is a