A reaction in which a molecule adds across a C=C or C=O double bond.

a chemical reaction in which one molecule is added to another

a reaction in which atoms are added to a molecule

A reaction in which the double or triple bond of an unsaturated compound opens up and other atoms add on to the molecule. Addition reactions are characteristic of the alkenes and alkynes.

A reaction in which a small molecule adds on across a double bond. Useful products from oil

An addition reaction, in chemistry, is in its simplest terms an organic reaction where two or more molecules combine to form a larger one.