Answer:
See explanation
Step-by-step explanation:
According to the atomic theory, when atoms of elements combine, they do so in simple ratios. This means that compounds contain atoms of elements in a fixed ratio irrespective of the source of the compound.
Hence the ratio of hydrogen to oxygen in water is fixed irrespective of the source of the water. Therefore, irrespective of the source from which the water is obtained. The same ratio of hydrogen to oxygen by mass is observed.