What can be concluded about the atom from knowing that oxygen-18 has an atomic number of 8?

I use this method to remember:
Let's use A as the mass number, and A = protons + neutrons 
Z is the atomic number, which is protons
To get neutrons, you subtract A from Z.
So in this sense, neutrons = 18 - 8 = 10 
I hope this helps with your work. :)

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.