CH18 Thermal Properties of Matter
 

Heat capacities

Suppose heat is input into a constant volume chamber containing a monatomic (单原子) gas,
for monatomic ideal gas only
Additional kinetic energy associated with rotation and vibration should be considered for diatomic and polyatomic gas.
Theorem of equipartition of energy (能量均分定理): The thermal energy of a system of particles is equally divided among all the possible energy modes (degree of freedom), that is,0.5kT per molecule.
 
Degrees of freedom (自由度)
Diatomic gas:         Polyatomic:         Monatomic solids:
 
Molecules speed distribution (分布)
Distribution function: P(v)
Number of molecules having the speed in the range between v and v+dv is given by
                                                        
The probability that a randomly chosen molecule will have a speed in the interval v to v+dv is P(v)dv.
 
Maxwell-Boltzmann distribution
 
 
 
Phase diagram (相图)
A graph showing different phases of matter, phase transitions, and phase equilibriums, etc.

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