Humber Admissions Practice Test

In a combustion reaction, what form of energy is primarily released?

1. Electrical Energy

2. Chemical Energy

3. Heat and Light Energy

4. Nuclear Energy

The correct answer is: Heat and Light Energy

In a combustion reaction, the primary form of energy released is heat and light energy. Combustion involves the chemical reaction between a fuel and an oxidant, typically oxygen, resulting in the formation of products such as carbon dioxide and water. During this process, chemical bonds in the reactants are broken, and new bonds are formed in the products, releasing energy. This energy is primarily released in the form of heat, which raises the temperature of the surrounding environment, and as light, which can be observed in flames. This characteristic of combustion reactions is what makes them useful for various applications, such as in engines, heating systems, and fire-making. Other forms of energy mentioned, such as electrical energy, chemical energy, and nuclear energy, do not represent the primary output of combustion reactions. While chemical energy in the reactants is converted to heat and light energy, it is the latter two forms that are specifically released as a result of the reaction.