When 425g of lead pellets are added to a graduated cylinder the water level rises from 25.0ml to 62.5ml so what is the density of the lead pellets?

Displaced volume :

62.5 mL - 25.0 mL => 37.5 mL

Mass = 425 g

Therefore:

D = m / V

D = 425 / 37.5

D =  11.33 g/mL

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.

I'm sorry i cant you if you don't list the elements : (