複選題26. Which of the following description(s) is/are correct? (A) Allotropic states are always thermodynamically unstable. (B) A material with high energy of formation must be more stable than a material with a lower energy of formation. (C) Adding sufficient heat to a system can cause it to undergo a process with positive change in Gibbs Free energy. (D) Gibbs free energy does not describe the progression rate of a process.