Final answer:
The phenomenon of spontaneous processes with decreased energy is described by the Second Law of Thermodynamics, which states that spontaneous processes result in increased total entropy of a system.
Step-by-step explanation:
The phenomenon of spontaneous processes proceeding with decreased energy is best described by the Second Law of Thermodynamics. According to the Second Law, all spontaneous processes result in increased total entropy of a system. This means that in a spontaneous process, the overall disorder or randomness of the system increases.