General properties of x-rays
- X-rays are the electromagnetic radiation of short wavelength ranging from 10-9 to 10-12 m and are invisible to normal human eye.
- They travel in straight line with the speed of light in vacuum (3×108 ms-1).
- They do not posses any charge i.e. X-rays are neutral.
- X-rays are not deflected by electric and magnetic field.
- They have high ionization power. They can ionize the gases through which they pass. Due to the high ionizing power of x-rays, they are used to cure cancer.
- X-rays affect photographic plate and they are even more effective than ordinary light.
- They produce fluorescence in some metals like Zinc sulphide, Bariumplatino cyanide, Cadmium tungestate, etc.
- X-rays show wave like properties like reflection, refraction, interference, diffraction and polarization similar to that of ordinary light.
- They can produce photoelectric effect and compton effect.
- Excess exposure of x-ray on living beings may cause harmful effects.
- They cannot pass through iron , lead, bone, etc and this property of x-ray is used in radiography. Absorption of x-ray increases with the increase in thickness and atomic number of the atoms in materials.
- Secondary x-rays are produced when they fall upon some metals.
- Frequency of x-ray is nearly equal to 1000 times more than that of visible light. Therefore, x-ray photons are much stronger than the photons of visible light.
- X-ray produce highly reactive OH– ions in solution. So, they can carry out chemical change.
- They are produced by the collision of fast moving electrons with the metal target of high atomic mass like tungsten, platinum, etc.
Hard x-rays and soft x-rays
Hard-x-raysThe x-ray having low wavelength, high frequency and high penetrating power are hard x-rays
Soft x-rays:The x-ray having high wavelength, low frequency and low penetrating power are soft x-rays.