Question

What type of chemical reaction occurs when two molecules combine to form one molecule?

Answer 1

The type of chemical reaction that occurs when two molecules combine to form one molecule is called a **combination reaction** (or synthesis reaction). In this type of reaction, two or more reactants combine to form a single product. An example of a combination reaction is when hydrogen gas and oxygen gas combine to form water (H₂ + O₂ → H₂O).