Chemistry Regents Practice Test 2025 – The All-in-One Guide to Exam Success!

In a decomposition reaction, a compound breaks down into simpler substances or elements. This process typically involves the breaking of chemical bonds within the compound, resulting in the formation of two or more products. For example, when water (H₂O) is decomposed by electrolysis, it separates into hydrogen gas (H₂) and oxygen gas (O₂). This transformation highlights the essence of decomposition reactions, which focus on the division of a single compound into multiple simpler entities.

The other options do not accurately represent the nature of a decomposition reaction. For instance, the formation of a new compound from reactants pertains to synthesis reactions, where elements or simpler compounds combine. Oxidation processes involve the transfer of electrons and are not exclusively tied to decomposition. Lastly, the formation of a precipitate refers to precipitation reactions, which involve solubility and ionic compounds rather than the breakdown of a compound.