Achemical change is like a physical change because no new substance is formed. agree or disagree and reason why

I disagree, because a physical change changes the form, and a chemical change is a process where one or more substances are altered into new substances.

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.