Chemistry – Reaction
When a chemical substance is transformed as a result of its interaction with another substance or with energy, a chemical reaction is said to have occurred.
A chemical reaction is therefore a concept related to the “reaction” of a substance when it comes in close contact with another, whether as a mixture or a solution; exposure to some form of energy, or both.
It results in some energy exchange between the constituents of the reaction as well as with the system environment, which may be designed vessels—often laboratory glassware.
Chemical reactions can result in the formation or dissociation of molecules, that is, molecules breaking apart to form two or more smaller molecules, or rearrangement of atoms within or across molecules.
Chemical reactions usually involve the making or breaking of chemical bonds. Oxidation, reduction, dissociation, acid-base neutralization and molecular rearrangement are some of the commonly used kinds of chemical reactions.
A chemical reaction can be symbolically depicted through a chemical equation. While in a non-nuclear chemical reaction the number and kind of atoms on both sides of the equation are equal, for a nuclear reaction this holds true only for the nuclear particles viz. protons and neutrons.