Darwinism designates a distinctive form of evolutionary explanation for the history and diversity of life on earth. Its original formulation is provided in the first edition of On the Origin of Species in 1859.
The enthalpy - or internal energy - of a substance is a function of its temperature and pressure. The change in internal energy with respect to change in temperature at fixed pressure is the Specific Heat at constant pressure - cp.
There is an energy barrier that separates the energy levels of the reactants and products. Energy must be added to the reactants to overcome the energy barrier, which is recovered when products are formed. The energy barrier is known as Ea, the activation energy. The activation energy is distinct from the Î´G, or free energy difference between the reactants and products. The Biology Project.