|Section 1.4 Page
|Radio waves have a longer wavelength than X rays,
therefore, they have a lower frequency and less energy. When radio waves
strike an object, they do not damage it. X rays have a much shorter
wavelength than radio waves, and therfore have a higher frequency and much
more eenergy. When X rays strike soft objects like human tissue, they
can cause damage.
|The human eye can detect wavelengths in the visible
range (400-700 nm).
|When white light is directed through a prism,
it separates into different colours. If white light did not consist
of different colours, it would remain white when passed through a prism.
|A continuous spectrum is an uninterrupted pattern
of colours observed when a beam of white light is passed through a prism.
An example of a continuous spectrum is a rainbow. A line spectrum
is discontinuous. The lines, produced when light emitted by an element
is directed through a prism, are separated by space with no colour. Hydrogen
gas has a line spectrum.
|a) It is not safe for the technician to
be in the same room during an X ray because the technician would be exposed
to X rays each time an X-ray scan is taken: as many as several hundreed scans
per year. This amount of exposure exceeds the recomended levels of X-rays
exposure for an iindividual. Patients are only exposed during thier
X-ray scan, therefore the risks are minimal.
|b) Only the desired area to be X-rays is
exposed; the rest of the body is covered with a lead apron, which X rays cannot
penetrate. technicians wear badges that measure the radiation levels
in the radiation areas, and keep detailed records of their cumulative lifetime