If a hypothesis is stated and outcome of the experiment is what was predicted, then it supports the hypothesis. if the experiment does not support the hypothesis, then the outcome was not what was predicted.
It's because of Avagadro's number.
- It is known as Avagadro's constant too.
- It states that at constant temperature one mole of any substance contain same number of atoms i.e n no of atoms
where

1: Decomposition reaction
2: Combination reaction
3: product
4: Reactant