towards an analysis of errors made by university students ... - DSpace

eing that 'quantum' is a more, inclusive term, which can be
applied to other things as well
as light - for instance - to
the vibration of whole atoms and molecules.
T8P - Text number 8 - Physics
THE QUANTUM THEORY OF RADIATION (Part two)
The quantum of radiant energy differs from
the
quantum of electricity, the electron, in a very important way.
The amount of charge is the same on all electrons: there
is
but one unit. The magnitude of this unit of radiant
energy,
however, is different for every different wave-length of
radiation. It is, in fact, proportional to the frequency, so
that the quantum of energy of extreme visible red radiation is
only half that of the extreme visible violet radiation,
which,
as we have said before, hîs double the frequency. The quantum
of an X-radiation
is very much greater than the quantum of any
visible
radiation.
The quantum of energy corresponding
to a given
species of radiation is found, then, by multiplying the frequency
by a certain fixed number, which is called Planck's universal
constant, and always indicated by Ih. Planck's constant enters
into every aspect of modern atomic physics and its
numerical
value has been found by at least ten different methods,
involving
such things as X-ray properties, the distribution
of energy in
black-body radiation, the frequencies of spectral lines, and so
on. All the methods give values agreeing to within a few parts
in ten
thousand.
Light, then, or radiation
in general, has a packet