p. 1889. Systems with variable numbers of particles
- Roger BowleyRoger BowleyDepartment of Physics University of Nottingham
- , and Mariana Sánchez
Abstract
This chapter explains that a system can have a variable number of particles when particles can enter or leave or because a reaction takes place inside the system. It cites a sealed vessel containing a pure substance with both liquid and gas phases present as an example that demonstrates the presence of a meniscus separating the gas from the liquid. This meniscus allows for determining which atoms to exist in the gas phase and in the liquid phase. The chapter also discusses how gas atoms can condense into liquid or how liquid can evaporate into gas. The chapter highlights the application of mathematical language to reactions of elementary particles or reactions that occurred in the early stages of the universe. It outlines the subject of reactions that occur frequently in science, such as solid-state physics, chemistry, and phase equilibrium.
