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 b
X-rays
- how they work
- X-rays are electromagnetic radiation
of high frequencies.
Their position in the electromagnetic spectrum is shown below:
- When a stream of very fast high-energy
electrons strike a metallic electrode (anode), the electrons are
slowed down, and some of them penetrate into the metal.
- The sudden “braking”
of the electrons produces an electromagnetic radiation of very
short wavelength "X-rays".
- One of the inner electrons
of an atom may be dislodged; the vacant place is taken by one
of the outer electrons, which leaps from an outer to an inner
“shell” and so emits energy in the form of X-ray radiation.
- These rays were discovered by
W. Rontgen, a German physicist, in 1895.
- Because of their short wavelength
X-rays can pass through objects which are opaque to ordinary light.
Shadow images of such objects can be made visible on a fluorescent
screen coated with barium platinocyanide.
Click here
for images
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