For a chemical reaction to occur, there must be a supply of reactants and the right conditions. The main requirements for a chemical reaction to take place are the presence of reactants, a catalyst, heat or pressure, and the correct pH level. The rate of reaction is affected by several factors that can be divided into two main categories: physical factors and chemical factors. Physical factors include temperature, surface area of the reactants, and the concentration of the reactants. Raising the temperature speeds up the chemical reaction, while increasing the surface area of the reactants increases the number of collisions between the particles. The concentration of the reactants also has an effect, as a more concentrated solution will increase the likelihood of successful collisions. Chemical factors include the type of catalysts used and the activation energy. A catalyst helps reduce the activation energy, which is the amount of energy required to start a reaction. The specific configuration of atoms involved in the reaction, referred to as the reaction mechanism, also affects the rate of reaction. Therefore, the requirements for a chemical reaction to occur are a supply of reactants, the right conditions, a catalyst, heat and/or pressure, and the correct pH level. Additionally, physical and chemical factors influence the rate of reaction, such as temperature, surface area, concentration, type o