During a chemical reaction, matter undergoes a change in chemical substance. Different types of chemical reactions include synthesis reactions, substitution reactions, chemical decomposition, acid-base reactions, double displacement reactions, redox reactions, combustion, isomerization and hydrolysis. Chemical reactions generally involve electron displacement, however, nuclear chemical reactions also involve changes in atoms' nuclei.
Excluding nuclear reactions, chemical reactions most often involve the breaking or formation of molecular bonds due to the movement of electrons between atoms. The transfer of electrons causes different compounds and molecules to form or disperse, and when conducted in a controlled setting by chemists, often produce a desired substance.
Synthesis reactions involve two different material substances combining to form a new substance. An example of a synthesis reaction is the combination of sodium and chlorine, creating sodium chloride, commonly known as table salt. The opposite of a synthesis reaction is a decomposition reaction, where a material substance is broken down into simpler substances.
Another commonly known type of chemical reaction is combustion. A simple example of this type of reaction is a campfire. In a combustion reaction, flammable material, such as wood, is combined with an oxidizer, such as air. While wood requires heat to begin a combustion reaction, not all combustion reactions require a heat source for ignition. When added to water, pure sodium ignites into a combustion reaction.