Introduction to Statistical Mechanics Flashcards
(17 cards)
What is an isolated system?
A system not connected to a resevoir
What is fixed for an isolated system?
E-energy
N-number of particles
V-volume
What is the potential energy for a simple harmonic oscillator (SHO)?
V=1/2 mω2x2
What are the energy levels for an SHO?
En=(n+1/2)ℏω
ℏ is (h bar or h /2pi)
What is the zero point energy?
The energy of the ground state (n=0)
What is a microstate?
A microscopic con figuration of the system
Very difficult to measure
What is a macrostate?
Any configuration with measurable properties
A macrostate can correspond to many microstates
How do we find the total number of microstates?
The total number of different combinations
What is the first assumption of SM?
All possible microstates in thermal equilibrium are equally likely to occur
What is the second assumption of SM?
The system’s dynamics are such that the microstate is constantly changing
What is the Ergodic hypothesis?
Given enough time, a system will explore all possible microstates, spending equal time in each
What are the different ensembles?
Microcanonical
Canonical
Grand canonical
What is the microcanonical ensemble?
An isolated system with fixed E
What is the grand canonical ensemble?
A system which can exchange energy and particles with a larger reservoir
What is fixed in the grand canonical ensemble?
Temperature and chemical potential
T and μ
What is the canonical ensmble?
A system which can exchange energy with a large reservoir
What is fixed for the canonical ensemble?
Temperature
