Melting is a process involving absorption of energy, which means that it is endothermic. A process whereby energy is released into the atmosphere or surrounding region is called an exothermic process.
Exothermic processes affect the environment by transferring heat from the substance while endothermic reactions can easily be characterized by a cooling effect experienced in the surrounding region. Below are a few examples of both endothermic and exothermic processes.
- Melting ice - when ice melts, it takes in energy from the outside region causing it to become liquid. Once ice has become liquid, it will evaporate as vapor which will still be an endothermic process
- Cooking an egg - this is also a process that involves absorption of heat energy
- More processes - additional endothermic processes include splitting a gas molecule, baking a cake, forming a cation from an atom in the gaseous stage, making an anhydrous salt from a hydrate and melting solid salts
- Freezing water - when water is freezing or turning into ice, it loses energy into the atmosphere causing a temperature rise in the environment
- Condensing water vapor - in order for vapor to change its state into liquid, it must lose heat energy into the surrounding environment
- More processes - additional exothermic processes include splitting of atoms, solidifying salts and forming an anion from an atom in the gaseous stage