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Science

The electromagnetic spectrum

Gamma radiation and X-rays

You should know some of the properties and uses of gamma radiation and X-rays.

Gamma radiation

Gamma waves have a very high frequency [frequency: The number of repetitions per second of a wave. The unit of frequency is the hertz, 'Hz'. ]. Gamma radiation cannot be seen or felt. It mostly passes through skin and soft tissue, but some of it is absorbed by cells.

Gamma radiation is used, among other things, for the following purposes.

  • to sterilise surgical instruments
  • to kill harmful bacteria in food
  • to kill cancer cells (note that lower doses of gamma radiation could lead to cells becoming cancerous)

X-rays

the x-ray shows the bones of a human chest in bright white light

Chest X-ray

X-rays have a lower frequency than gamma radiation. Like gamma rays, they cannot be seen or felt. X-rays mostly pass through skin and soft tissue, but they do not easily pass through bone or metal.

X-rays are used to produce photographs of bones to check for damage such as fractures. They are also used in industry to check metal components and welds for cracks or other damage.

Lower doses of X-rays can cause cells to become cancerous, so precautions are taken in hospitals to limit the dose received by patients and staff when X-ray photographs are taken.

For more information about gamma radiation, visit Radioactive substances.

Back to Radiation and the Universe index

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