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

An exothermic reaction is characterized by the release of energy, typically in the form of heat, to the surroundings when reactants are transformed into products. The process of respiration is a prime example of an exothermic reaction. During respiration, glucose is broken down in the presence of oxygen to produce carbon dioxide, water, and energy. The energy released is vital for various biological processes, making respiration fundamentally important for living organisms.

In contrast, other processes listed, such as the evaporation of water and the melting of ice, are endothermic reactions. These processes absorb energy from the surroundings to occur, leading to a decrease in ambient temperature. Photosynthesis also absorbs energy, as it converts carbon dioxide and water into glucose and oxygen using sunlight. Understanding the energy dynamics of these reactions helps clarify why respiration stands out as an exothermic reaction among the options provided.