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X-rays are very
high frequency waves, and carry a lot of energy. They will pass
through most substances, and this makes them useful in medicine
and industry to see inside things.
X-rays are given
off by stars, and strongly by
some types of nebula.
An X-ray machine works by firing
a beam of electrons at a "target". If we fire the electrons
with enough energy, X-rays will be produced. |
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Lower energy
X-Rays don't pass through tissues as easily, and can be used to
scan soft areas such as the brain

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X-rays are
used by doctors to see inside people.
They pass easily through soft tissues, but not so easily through
bones. We send a beam of X-Rays through the patient and onto a piece
of film, which goes dark where X-Rays hit it. This leaves white
patches on the film where the bones were in the way.

Sometimes a
doctor will give a patient a "Barium Meal", which is a
drink of Barium Sulphate. This will absorb X-rays, and so the patient's
intestines will show up clearly on a X-Ray image.
X-Rays are also
used in airport security checks,
to see inside your luggage. They are also used by astronomers
- many objects in the universe emit X-rays, which we can detect
using suitable radio telescopes. |