How do chemical reactions occur?

Chemical reactions occur when atoms or molecules interact to form new substances. This process involves the breaking and forming of chemical bonds, leading to changes in the arrangement of atoms. Here’s a step-by-step overview of how chemical reactions happen:

1. Collision of Reactants: For a chemical reaction to occur, the reactant molecules or atoms must collide with one another. These collisions provide the opportunity for bonds to break and form new ones.

2. Activation Energy: Not all collisions lead to a reaction. The colliding particles must have enough energy to overcome the activation energy, which is the minimum energy required to initiate the reaction. This energy barrier must be surpassed for the reaction to proceed.

3. Formation of Transition State: When the reactants collide with sufficient energy, they form an intermediate structure called the transition state. In this state, bonds in the reactants are partially broken, and new bonds in the products are partially formed.

4. Breaking and Forming Bonds: In the transition state, existing bonds are broken, and new bonds are formed, resulting in the conversion of reactants into products. The arrangement of atoms changes, leading to the creation of new substances with different properties.

5. Energy Change: Chemical reactions either release energy (exothermic reactions) or absorb energy (endothermic reactions). In exothermic reactions, energy is released, usually as heat or light, while in endothermic reactions, energy is absorbed from the surroundings.

6. Products Formation: Once the reaction is complete, the transition state collapses into the final products. These products are the new substances formed as a result of the chemical reaction.

7. Equilibrium (in Reversible Reactions): Some reactions are reversible, meaning they can proceed in both forward and backward directions. Over time, these reactions may reach a state of equilibrium, where the rates of the forward and reverse reactions are equal, and the concentrations of reactants and products remain constant.

Chemical reactions are fundamental to all biological and chemical processes, driving everything from the metabolism in living organisms to industrial manufacturing processes.