What is a characteristic of a decomposition reaction?

A decomposition reaction is defined by its ability to break down a compound into simpler substances or constituent elements. This process typically involves the input of energy in the form of heat, light, or electricity, which provides the necessary drive to overcome the bonds holding the compound together. During a decomposition reaction, a single compound is broken apart, resulting in products that can be elements or smaller compounds.

For instance, when water (H₂O) is subjected to electrolysis, it decomposes into hydrogen gas (H₂) and oxygen gas (O₂). The key characteristic here is that the original compound is split into simpler forms, clearly identifying this type of reaction. Other aspects related to the process, such as needing a catalyst or resulting in a gas, may happen in specific cases of decomposition reactions but are not universally true for all decomposition scenarios. The fundamental nature of such a reaction is its capacity to simplify complex molecules into more basic units, making the correct answer evident.