User:Sadi Carnot/Sandbox9

From Wikipedia, the free encyclopedia

Every earth-bound system is an atomic-molecular system. Collections of smaller interactive atomic or molecular systems, over time, react to form larger molecular systems. Molecular systems evolve or behave according to the following atomic-molecular evolution principle:

Date	Person	Version
1913	Niels Bohr	In any molecular system consisting of positive nuclei and electrons in which the nuclei are at rest relative to each other and the electrons in circular orbits, the angular momentum or every electron round the centre of its orbit will be in the permanent state of the system equal to h / 2π, where h is Planck’s constant, and we shall assume that a configuration satisfying this condition is stable if the total energy of the system is less than in any neighboring configuration satisfying the same condition of the angular momentum of the electrons.
1952	Charles Coulson	Two atoms form a molecule because there is a lowering of the total energy when they come together.
1960	Linus Pauling	The configuration for the normal state of any molecule is that corresponding to the minimum value of the energy function, i.e. the electronic energy of the molecule as a function nuclear configuration, which corresponds to the motion of the electrons in the fields of the atomic nuclei, a minimum which thus gives the molecule a maximum stability.
2002	Britannica	When atoms approach one another, their nuclei and electrons interact and tend to distribute themselves in space in such a way that the total energy is lower than it would be in any alternative arrangement. If the total energy of a group of atoms is lower than the sum of the energies of the component atoms, then they bond together and the energy lowering is the bonding energy.
2005	Mark Winter	The geometry that will be adopted by a molecule will be that in which the total energy for all the electrons in that molecule is a minimum.

In short, the valence electrons of any molecular system will tend to evolve in such a manner so as to achieve the configuration of maximum stability. Thermodynamically, the Gibbs free energy is simply a measure of the chemical work involved in each of these processes. Another way of stating this evolution process, according to the combined law of thermodynamics, for constant temperature, constant pressure, systems, such as earth, is that each system will tend to configure or evolve in such a manner so as to minimize its Gibbs free energy.