What occurs in a synthesis reaction?

In a synthesis reaction, a single product is formed from simpler reactants. This type of reaction can be represented by the general equation A + B → AB, where A and B are the reactants that combine to create a more complex product, AB. The key characteristic is the combination of two or more substances to produce a larger compound.

Synthesis reactions are foundational in chemistry because they illustrate how simpler materials can combine in specific ways to create more complex molecules. This process is vital in various biological and industrial applications, such as the formation of glucose from carbon dioxide and water during photosynthesis, demonstrating the importance of these reactions in nature.

The other options describe different types of chemical reactions. The formation of multiple products from one reactant characterizes decomposition reactions, where a complex substance breaks down into simpler components. The third option pertains to single replacement or double replacement reactions, where reactants exchange components. The last choice refers to endothermic reactions, which may absorb heat energy but is not specific to synthesis reactions. Through understanding these concepts, one can clearly differentiate synthesis reactions from other types of chemical processes.