To use all functions of this page, please activate cookies in your browser.
my.chemeurope.com
With an accout for my.chemeurope.com you can always see everything at a glance – and you can configure your own website and individual newsletter.
 My watch list
 My saved searches
 My saved topics
 My newsletter
Closed systemA closed system is a system in the state of being isolated from the environment. It is often used to refer to a theoretical scenario where perfect closure is an assumption, however in practice no system can be completely closed; there are only varying degrees of closure. Additional recommended knowledgeIn physics, a closed system can exchange heat and work, but not matter, with its surroundings. In contrast an isolated system can exchange neither heat nor matter with the surroundings. For a simple system, with only one type of particle (atom or molecule), this amounts to a constant number of particles. However, for systems which are undergoing a chemical reaction, there may be all sorts of molecules being generated and destroyed by the reaction process. In this case, the fact that the system is closed is expressed by saying that the total number of each elemental atom is conserved, no matter what kind of molecule it may be a part of. Mathematically: where N_{j} is the number of jtype molecules, a_{ij} is the number of atoms of element i in molecule j and b_{i}^{0} is the total number of atoms of element i in the system, which remains constant, since the system is closed. There will be one such equation for each different element in the system. In quantum mechanics confusingly, a closed system is equivalent to an isolated system, and a system that can exchange energy with the surroundings is referred to as an open system^{[1]}. Notes
See also

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Closed_system". A list of authors is available in Wikipedia. 