If i have 9 gram of H2O find its atomic mass and proportion

Answer 1

2 hydrogen = 2 g
1 Oxygen = 16 g

18 grams so you had 9 grams 9/18 = 1/2 is the proportion. This would be 1/2 of a mole of water.

or are you asking the proportion by mass of H to O

2/16 = 1/8