Final answer:
Chemical reactions involve the conversion of thermodynamic energy and kinetic energy. Thermodynamic energy changes determine if a reaction is exothermic or endothermic, while kinetic energy is needed to overcome activation energy. Potential energy stored in chemical bonds is often converted into other forms like mechanical kinetic energy.
Step-by-step explanation:
Chemical reactions always involve changes in energy. There are two main types of energy relevant to reactions: thermodynamic energy and kinetic energy. Thermodynamic energy is related to the energy changes when reactants convert to products, which can be either released or absorbed. This type of energy change defines whether a reaction is exothermic or endothermic. Kinetic energy, on the other hand, is the energy that reacting molecules must possess to overcome the energy barrier to react and form products, known as the activation energy.
In the course of a reaction, chemical bonds break and new ones form. The energy stored in these bonds is a form of potential energy. When substances convert, there is a conversion of energy forms - for example, chemical potential energy can be converted to mechanical kinetic energy, such as in a car engine where the combustion of gasoline moves pistons.