What type of reaction involves the breaking of a compound into its component parts?

A decomposition reaction is characterized by the process of breaking down a compound into its simpler constituents, which can include elements or smaller compounds. This type of reaction can be represented generally by the formula:

[ AB \rightarrow A + B ]

where ( AB ) is the compound being decomposed into its parts ( A ) and ( B ). Decomposition reactions often require an input of energy, which can come in the form of heat, light, or electricity.

For example, when calcium carbonate (( CaCO_3 )) is heated, it decomposes into calcium oxide (( CaO )) and carbon dioxide (( CO_2 )).

This is distinct from other types of reactions listed. A combination reaction involves the merging of two or more substances to form a single product; a synthesis reaction refers to a similar process where elements combine to form a more complex compound. Combustion reactions involve the reaction of a substance with oxygen, typically resulting in the release of energy in the form of heat and light, producing new substances, mainly oxides.

Overall, a decomposition reaction is specifically about breaking down a compound, which is what makes it the correct answer to the question posed.