Answer:
Water breaking down into hydrogen and oxygen is a decomposition reaction
Hydrogen and oxygen combining to form water is a synthesis reaction
Explanation:
A decomposition reaction is a chemical reaction that involves the breakdown of a chemical reactant entity into two or more simpler product fragments
Water H₂O undergoes a decomposition reaction by breaking down into hydrogen, H₂,, and oxygen, O₂, as follows;
2H₂O (l) → 2H₂ (g) + O₂ (g)
A synthesis reaction is a reaction that involves the chemical combination of two or more dissimilar molecules or atoms to produce a different compound or molecule
Water, H₂O, is formed by a synthesis reaction of hydrogen, H₂,, and oxygen, O₂, combining as follows;
2H₂ + O₂ → 2H₂O
