Which of the following has 1.2 times 10 (24) hydrogen atoms

Step 1: Find the mole ratio for each of the choices, and then multiply mole ratio by the 1 mole of H20 and Avogadro's number (6.022 x 10^23), so you will have this for each choice

1 mole H2O ( ratio /ratio) (6.022 x 10^23 / 1 mole) = atoms

One: 1 mole of water (H2O

You have 2 mole of H to 1 mole H2O, so the ratio is 2 to 1 or 2:1, and you have

1 mol H2O x (2 mol H / 1 mol H2O) x (6.022x10^23 atoms H / mol H) = 1.2 x 10^24

So, we can stop right here, because we have the value you were looking for.  If you want, you can work the other 3 in the same manner.

1 mol CH4 x (4 mol H / 1 mol CH4) x (6.022x10^23 atoms H / mol H) =

2 mol NH3 x (2 mol H / 1 mol NH3) x (6.022x10^23 atoms H / mol H) =

2 mol H2 x (2 mol H / 1 mol H2) x (6.022x10^23 atoms H / mol H) =

I tried as hard as i could then i noticed i answered this on my test and i got it right so i just typed it all in

1 mole of water (H2O)

Explanation:

2 hydrogen atoms so 2 x 1 mole (or 6.022 x 10^23 atoms) = 1.2 x 10^24 atoms

answers: to make sure that all of the broken pieces of tablet were added to the water, to allow for fair comparison of all three trials, with different particle sizes to avoid experimental error