In a simple manner, with respect to STP reacting systems, a<unk> eneral rule of thumb is:
Hence, out of this<unk> eneral natural tendency, a quantitative measure as to how near or far a potential reaction is from this minimum is when the calculated energetics of the process indicate that the change in<unk> <unk>  is negative.  Essentially, this means that such a reaction will be favored and will release energy.  The energy released equals the maximum amount of work that can be performed as a result of the chemical reaction.  Conversely, if conditions indicated a positive<unk> , then energy--in the form of work--would have to be added to the reacting system to make the reaction<unk> o.
Gibbs free energy
Free energy
Spin quantum number
Potential energy
Quantum yield
Gas constant
Extraction ratio
Molecular mass