Cambridge IGCSE Chemistry · Syllabus 0620 · Chemical Energetics
Enthalpy Change
What is Enthalpy Change?
The transfer of thermal energy during a chemical reaction, given the symbol delta H; it is negative when the reaction transfers thermal energy to the surroundings and positive when the reaction takes thermal energy in from the surroundings.
This definition is part of the Chemical Energetics chapter in Cambridge IGCSE Chemistry.