The law of conservation of matter states that matter can be neither created nor destroyed. Your friend shows you the following chemical equation:
CaCO CaO+CO.
I
He says that because the oxygen atoms are split between two different molecules in the
products, the equation does not support the law of conservation of matter is your friend right?
Explain your answer.

Hey how did you manage to type such a big lab report

The answers is a nuclear changes

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.

Aquantity of that isotope to decay to 1/2 of  its original value