Combination Reaction
A reaction in which two or more substances unite to form a single product.
Formula / equation
A + B → AB
Unit
Dimensionless
In depth
Also called synthesis or direct combination, these reactions are usually exothermic because bonds are formed without any being broken in a complex framework. They may join two elements, an element and a compound, or two compounds, and they are the simplest route to binary compounds.
Examples in the real world
2Mg + O₂ → 2MgO; CaO + H₂O → Ca(OH)₂ releasing enough heat to boil water.