spontaneity; spontaneous process; spontaneous reaction. A spontaneous process occurs because of internal forces; no external forces are required to keep the process going, although external forces may be required to get the process started. For example, the burning of wood is spontaneous once the fire is started. The combination of water and carbon dioxide to reform the wood and oxygen is NOT spontaneous
a spontaneous change will occur by itself. However, there is nothing in the concept of a spontaneous reaction that tells how fast the reaction is occurring (this depends on the temperature, and the activation energy). A spontaneous reaction may be either fast, or slow. For a reaction to occur spontaneously there must be an increase in the entropy of the universe, or the Gibbs free energy change must be less than 0.
Generation - The development of living organisms from non-living matter. Louis Pasteur proved that spontaneous generation did not occur regularly. He is quoted as saying, "Life is a germ, and a germ is Life. Never will the doctrine of spontaneous generation recover from the mortal blow of this simple experiment."