Decomposition
Step-by-step explanation:
A synthesis reaction is a type of chemical reaction in which two or more simple substances combine to form a more complex product.
Since there is only one reactant and it is broken into smaller components,
it is not a synthesis reaction.
A decomposition reaction is a type of chemical reaction in which one reactant yields two or more products.
Since in our question,there is one reactant and it is broken to yield two products,it is a decomposition reaction.