Answer:
2.676e22 atoms of Hydrogen
Explanation:
Knowing the density of water is 1g/ml, 1(g/ml)*0.4ml=0.4 grams of H2O. Knowing that there are 16 grams of H2O in 1 mole of H2O, we can set up a unit conversion of 0.4 Grams H2O * [tex]\frac{1 mol H_2O}{18 grams H_2O}*\frac{2 mol H}{1 mol H_2O} *\frac{6.022e23 atoms of H}{1 mol H}[/tex]=
2.676e22 atoms of Hydrogen.