In chemistry an activated complex is a transitional structure in a chemical reaction that results from an effective collision between molecules and that persists while old bonds are breaking and new bonds are forming. Chemistry (from Egyptian kēme (chem meaning "earth") is the Science concerned with the composition structure and properties A chemical reaction is a process that always results in the interconversion of Chemical substances The substance or substances initially involved in a chemical reaction are called A collision is an isolated event in which two or more bodies (colliding bodies exert relatively strong forces on each other for a relatively short time In Chemistry, a molecule is defined as a sufficiently stable electrically neutral group of at least two Atoms in a definite arrangement held together by A chemical bond is the physical process responsible for the attractive interactions between Atoms and Molecules and which confers stability to diatomic and polyatomic It is therefore a range of molecular geometries along the reaction coordinate. In Chemistry, a reaction coordinate is an abstract one-dimensional Coordinate which represents progress along a Reaction pathway.