The Collision Theory
Atoms, molecules, or ions must collide before they can react with each other. Atoms must be close together to form chemical bonds. This premise is the basis for a theory that explains many observations regarding chemical kinetics, including factors affecting reaction rates.
The collision theory is based on the postulates that (i) the reaction rate is proportional to the rate of reactant collisions, (ii) the reacting species collide in an orientation allowing contact between...

Chemical Kinetics
The reaction rate is the speed at which a chemical reaction occurs. The reaction rate is defined as the change in concentration of a component in the reaction with time. The speed of a reaction depends on several factors, including the concentration of reactants and the temperature at which the reaction is performed. Each reactant contributes to the speed of the reaction by a specific factor. This relationship is defined by the reaction rate law.
Rate Law
The rate law is an...

Source: Smaa Koraym at Johns Hopkins University, MD, USA

Source: Smaa Koraym at Johns Hopkins University, MD, USA

In a nonhomogeneous rod made up of steel and brass, restrained at both ends and subjected to a temperature change, several steps are involved in calculating the stress and compressive load. Due to the problem's static indeterminacy, one end support is disconnected, allowing the rod to experience the temperature change freely. Next, an unknown force is applied at the free end, triggering deformations in the rod's steel and brass portions. These deformations are then calculated and added...

Whether solid, liquid, or gas, a substance's state depends on the order and arrangement of its particles (atoms, molecules, or ions). Particles in the solid pack closely together, generally in a pattern. The particles vibrate about their fixed positions but do not move or squeeze past their neighbors. In liquids, although the particles are closely spaced, they are randomly arranged. The position of the particles are not fixed—that is, they are free to move past their neighbors to...