Nonmetals form bonds by sharing electrons to complete their valence shell and increase stability.

Non metals form ionic bonds by gaining and losing electrons to complete their valence she'll and increase stability. Metals form covalent bonds by sharing electrons.

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.