Chemical Reaction

Name:
Chemical Reaction
Detailed information:
A chemical change that may occur in several ways, e.g., combination, replacement, by decomposition, or by some modification of these. Reactions are endothermic when heat is needed to maintain them and exothermic when they evolve heat. All chemical reactions are in balance, i.e., the numbers of atoms of the various elements in the reacting substances are always equal to the numbers of atoms in the reaction products. Common types of reactions are oxidation, reduction, ionization, combustion, polymerization, hydrolysis, condensation, enolization, saponification, rearrangement, etc. Chemical reactions involve rupture of only the bonds that hold the molecules together and should not be confused with nuclear reactions, where the atomic nucleus is involved. A reversible reaction is one in which the reaction product is unstable and thus changes back into the original substance spontaneously. In a complete reaction, the activity goes to completion and is indicated by an arrow →; if heat or a catalyst is used, it is indicated by a symbol or word, usually placed in small type above the arrow as:Δcatalyst→→