The various atomic masses of the same element are called<u> isotopes</u>. They have the same number of protons but different number of neutrons.
2 atome nitrogen , 1 is correct
Answer:
15.2 g H2
Explanation:
2H2O -> 2H2 + O2
9.06 x 10^24 molecules x (1 mol/6.022 x 10^23 molecules) x (2 mol H2/2 mol H2O) x (1.008 g/1 mol) = 15.2 g H2