A student recorded the mass of a sample of copper to be 23.67 grams and its volume to be 2.64 ml. How many significant digits should the student use when reporting the density?

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.

Any vitamins or supplements can be obtained without prescription and are widely used as alternative from western medications. most supplements are not valued by the fda or any other drug and food agencies.

Heating it up with cause a quicker reaction time