After
reading this section you will be able to do the following:
Explain
what the electromagnetic spectrum is and how scientists use
it.
So far we have learned about the atom,
the phenomenon of radioactivity, and we have looked at both nuclear
reactions and X-ray generation. We already know that X- and gamma
rays differ only in their source of origin or how they are generated.
There are, however, very distinct characteristics associated with
these energy forms. Two key points to remember about the characteristics
of radiation are that X- and gamma rays are not bits of matter,
they are electromagnetic wave forms possessing no charge and no
mass, and they can be characterized by frequency, wavelength,
and velocity. Let's take a closer look at the characteristics
of these wave forms so that we may better understand the nature
of them.
What are Electromagnetic
waves?
X- and gamma rays are part of what
scientists refer to as the electromagnetic spectrum. They
are waveforms that are part of a family in which some of the relatives
are very familiar to us, such as light rays, infrared heat rays,
and radio waves. However, X- and gamma rays cannot been seen,
felt, or heard. In other words, our normal senses cannot detect
them. Since X- and gamma rays have no mass and no electrical charge,
they are not influenced by electrical and magnetic fields and
will travel in straight lines. Continued research over the years
since Roentgen’s discovery indicated that the radiation possesses
a dual character. Acting somewhat like a particle at times and
like a wave at other times. The name that has been given to the
small "packets" of energy with these characteristics
is "photon." It is said that the radiation photon
is a wave that is both electric and magnetic in nature.
This diagram shows the electromagnetic
spectrum. Notice the changes in wavelengths of the various wave
forms.
Every point across the
spectrum represents a wave form of differing wavelength. It should
be noted that the lines between the groupings are not precise,
and that each group phases into the next.
Wave forms may be graphically represented
as following:
Take the following links
to learn more!
Take this link to learn about the
definition of a wavelength:
