Internal Energy
Crystals with line defects are thermally unstable as its ethalpy change increases more than its entropy change. This leads to an increased in Gibbs free energy.
Gibbs energy accounts for both enthalpy (heat) and entropy (disorder) in a system. A reaction will be spontaneous if the Gibbs energy change is negative, which occurs when enthalpy is negative (exothermic) and/or entropy is positive (increased disorder). The relationship between Gibbs energy, enthalpy, and entropy is described by the equation ΔG = ΔH - TΔS, where T is temperature in Kelvin.
Energy, E.There are two types of chemical reactions. Reactions which produce energy are called exothermic reactions, while reactions which consume energy are called endothermicreactions. Generally, an exothermic reaction can be written such as Reactants → Products + Energy An endothermic reaction can be written such as: Reactants + Energy → Products