In 1895, Wilhelm Conrad Roentgen, a German physicist, observed while doing some experiments with a discharge tube that when cathode rays are allowed to fall on a metal target called anticathode placed in their path, new kinds of radiations are produced. These radiations are called X-rays.
Properties of X-rays
X-rays have the following properties:
They travel in straight lines
They are not bent in an electric or magnetic field
They can pass through opaque objects like black paper
They can affect a photographic plate wrapped in black paper Later studies on X-rays revealed that they are in fact electromagnetic waves of very short wavelengths.
Uses of X-rays
The discovery of X-rays has brought about revolutionary changes in medical science. X-rays are used to take pictures of fractured bones. Solid bone does not allow X-rays to pass through it and it is seen as an opaque image on X-ray film. The crack between two parts of a fractured bone can be seen easily on the X-ray film. Other problems, like infections in the lungs can be diagnosed with the help of X-rays.