Which of the following is an example of an exothermic reaction?

The combustion of fuels is an example of an exothermic reaction because it releases energy in the form of heat and light. During combustion, chemical bonds in the fuel break and new bonds form with oxygen, resulting in the formation of products such as carbon dioxide and water. As these products form, energy is released, making the surroundings warmer. This release of energy is characteristic of exothermic reactions, where the total energy of the products is lower than that of the reactants.

In contrast, the melting of ice involves a phase change from solid to liquid that requires the absorption of heat from the surroundings, making it an endothermic process. Similarly, the dissolution of salt in water can be endothermic or exothermic depending on the specific conditions, but generally, it often absorbs heat. The evaporation of water also requires energy input, as it involves breaking intermolecular forces to transform liquid water into vapor, which is another endothermic process.