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Challenge: Problem 1

As we mentioned in the PRESENTATION, it is possible to put the Maxwell-Boltzmann statistics to experimental tests. In 1920 Stern did a beautiful experiment for this purpose using silver vapour (see fig. 8.6). A beam of silver atoms was produced by means of a collimator and a shutter. As the shutter was briefly opened, a plate moved at high speed in front of the beam. The varying density of silver deposited on the plate was then a measure of the velocity distribution.

Consider the following points:

(i) what kind of energy do we attribute to the silver atoms?

(ii) what concepts do we use in order to calculate the energy distribution?

(iii) how then do we calculate the velocity distribution?

Try to answer these questions by selecting items from the RESPONSE ARRAY.

1
break up of material particles into smaller particles		 2
momentum or velocity space		 3
energy cells that accommodate only one particle at a time		 4
number of arrangements corresponding to the distribution of energy		 5
mass of particles
6
translational kinetic energy		 7
average thermal energy of a particle is an integral multiple of 1/2 kT		 8
number of particles possible in a particular energy cell		 9
internal energy states of particles		 10
at absolute zero, entropy is zero
11
state of greatest probability		 12
number of degrees of freedom for thermal energy		 13
rotational energy		 14
intrinsic structure of energy cells, such as their size and the "separation" betweeen them		 15
= ( 1 / kT )
16
zero point energy of a system		 17
vibrational energy		 18
effective continuum of energy states		 19
internal energy is the sum of the energies of the particles		 20
thermal equilibrium entails maximum entropy