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Consider a hypothetical atom that has just two states: a ground state with energy zero and an excited state with energy 2 eV. Draw a graph of the partition function for this system as a function of temperature, and evaluate the partition function numerically at T = 300 K, 3000 K, 30,000 K, and 300,000 K.

Short Answer

Expert verified

Therefore the partition functions are:

Z(300K)=1+2.512×10-34Z(3000K)=1.000436Z(30000K)=1.461Z(300000K)=1.925

Step by step solution

01

Given information 

A hypothetical atom that has just two states: a ground state with energy zero and an excited state with energy 2 eV.

02

Explanation 

The partition function is equal to the total of all Boltzmann factors, i.e.

Z=∑se-E(s)/kT

Given two states, a ground state with zero energy and an excited state with e =2eV, the partition function is

Z=e0+e-ϵ/kTZ=1+e-ϵ/kT

Substituting ϵand Boltzmann's constant k=8.617×10-5eV/K

Z=1+e-2eV/8.617×10-5eV/KTZ=1+e-23210K/T

Using python to plot the partition function as a function of temperature, the code is:

The graph is:

03

Calculations

At temperature of T= 300 K, the value of the partition function is:

Z(300K)=1+e-23210K/300KZ(300K)=1+2.512×10-34

At temperature of T= 3000 K, the value of the partition function is:

Z(3000K)=1+e-23210K/3000KZ(3000K)=1.000436

At temperature of T= 30000 K, the value of the partition function is:

Z(30000K)=1+e-23210K/30000KZ(30000K)=1.461

At temperature of T= 300000 K, the value of the partition function is:

Z(300000K)=1+e-23210K/300000KZ(300000K)=1.925

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Most popular questions from this chapter

At very high temperatures (as in the very early universe), the proton and the neutron can be thought of as two different states of the same particle, called the "nucleon." (The reactions that convert a proton to a neutron or vice versa require the absorption of an electron or a positron or a neutrino, but all of these particles tend to be very abundant at sufficiently high temperatures.) Since the neutron's mass is higher than the proton's by 2.3 x 10-30 kg, its energy is higher by this amount times c2. Suppose, then, that at some very early time, the nucleons were in thermal equilibrium with the rest of the universe at 1011 K. What fraction of the nucleons at that time were protons, and what fraction were neutrons?

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