11. An isolated system has a fixed total energy and mass. 12. The study of equilibrium ensembles of isolated systems is the focus of statistical thermodynamics. 13. It is important to note that isolated systems are not equivalent to closed systems. 14. In an isolated system , thermodynamic equilibrium by definition persists over an indefinitely long time. 15. Truly perfectly isolated systems do not occur in nature, and always are artificially prepared. 16. For isolated systems , an adiabatic change allows no heat to flow in or out. 17. For isolated systems the first four equations are the familiar conservation equations in physics. 18. Momentum conservation is always true for an isolated system not subject to resultant forces. 19. That is, we are dealing with an isolated system . 20. In particular, some writers use'closed system'where'isolated system 'is here used.
