In what type of reaction do substances combine to form a more complex substance?

A synthesis reaction is characterized by the combination of two or more simpler substances to create a more complex substance. This type of reaction can be represented by the general formula where reactants, often elements or simpler compounds, chemically bond together to form a single, more complex product.

In many cases, this process facilitates the formation of new bonds and broader structures, showcasing the principles of chemical interactions. For example, when hydrogen gas reacts with oxygen gas, they synthesize to form water, a more complex substance.

Synthesis reactions play a crucial role in numerous biochemical processes and industrial applications, making them fundamental in understanding chemical behaviors. In contrast, decomposition reactions involve breaking down a complex substance into simpler components, while replacement reactions involve the exchange of ions or elements, thereby not leading to a straightforward combination into a more complex form.