an oxygen atom combines with 1.5 hydrogen atoms to form a water molecule. why is this inconsistent with dalton's atomic theory? an oxygen atom combines with 1.5 hydrogen atoms to form a water molecule. why is this inconsistent with dalton's atomic theory? atoms combine in 1:1 ratios to form compounds. atoms of one element cannot change into atoms of another element. oxygen and hydrogen atoms do not combine. atoms combine in simple, whole-number ratios to form compounds.
