Energy change refers to the difference in energy between the initial and final states of a system. It can be positive (endothermic) or negative (exothermic), depending on whether energy is absorbed or released during a process.
Related terms
Heat Transfer: The process of thermal energy moving from one object or system to another due to temperature differences.
Enthalpy: The heat content of a system at constant pressure, which includes both its internal energy and the work it can do on its surroundings.
Calorimeter: A device used to measure the heat exchanged between a chemical reaction and its surroundings.