Why are decomposition reactions called the opposite of combination reactions? Write equations for these reactions.
Decomposition reactions are called the opposite of combination reactions because in a combination reaction, two or more substances combine to form a new single substance, whereas in a decomposition reaction, a single substance decomposes to give two or more substances. In a combination reaction, reactants combine, while in a decomposition reaction, a single reactant breaks down.
An example of a combination reaction provided in the text is the formation of water:
A decomposition reaction involves a single substance breaking down into simpler substances, though a specific chemical equation for this process is not included in the provided context.
Explanation
The answer is derived directly from the definitions provided in the context. The text explicitly states that combination reactions involve forming a single substance, while decomposition involves breaking a single substance into two or more, making them opposites. The equation for the combination reaction (formation of water) is the only valid example of a combination reaction found in the provided text chunks (the burning of natural gas produces two products, so it does not fit the strict definition of a single product). No specific decomposition equation is present in the context, so the answer relies on the textual definition provided.