How many molecules (not moles) of nh3 are produced from 6.96×10−4 g of h2? express your answer numerically as the number of molecules?

Number of moles = mass / molar mass
number of moles of H2 = (6.96×10−4) / (2)(1) = 3.48*10^-4 moles

The equation that describes the formulation of NH3 is:
N2 + 3H2 > 2NH3
From the balanced chemical equation, we can see that:
3 moles of H2 produces 2 moles of NH3
Based on this, to know the number of moles of NH3 produced from 3.48*10^-4 moles of hydrogen, we will do cross multiplication as follows:
number of moles = (3.48*10^-4*2) / (3) = 2.32*10^-4 moles

Now, one mole of any element contains Avogadro's number of molecules. Therefore, number of molecules in 2.32*10^-4 moles can be calculated as follows:
number of molecules = 2.32 * 10^-4 * 6.022 * 10^23 = 1.397 * 10^20 molecules

257 grams h2o i think

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.