Friday, July 8, 2011

X-ray by Gavin, Nur Nadiah & Yan Jin

Introduction to X-Rays
X-radiation (composed of X-rays) is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers. They are shorter in wavelength than UV rays and longer than gamma rays.

Medical X-rays are a significant source of man-made radiation exposure, accounting for 58% in the United States in 1987, but since most radiation exposure is natural (82%), medical X-rays only account for 10% of total American radiation exposure.


Are X-Rays bad for you?
The problem is that X-rays are a form of ionizing radiation. When normal light hits an atom, it can't change the atom in any significant way. But when an X-ray hits an atom, it can knock electrons off the atom to create an ion, an electrically-charged atom. Free electrons then collide with other atoms to create more ions.

An ion's electrical charge can lead to unnatural chemical reactions inside cells. Among other things, the charge can break DNA chains. A cell with a broken strand of DNA will either die or the DNA will develop a mutation. If a lot of cells die, the body can develop various diseases. If the DNA mutates, a cell may become cancerous, and this cancer may spread. If the mutation is in a sperm or an egg cell, it may lead to birth defects. Because of all these risks, doctors use X-rays sparingly today.


Random facts about X-Rays
  • When the wavelengths of light decrease, X-Rays increase in energy
  • Smaller wavelengths, and thus have higher energy compared to ultraviolet waves
  • X-ray detectors collect photons of X-ray light
  • Due to Earth’s thick atmosphere, no X-rays are able to penetrate from outer space to Earth’s surface
  • X-rays cannot be felt by us
  • Because bones are dense and absorb more X-rays compared to the skin, silhouette of the bones are left on he X-ray film while the skin appears transparent.
  • Things in space that emits X-rays, which include black holes, neutron stars, binary star systems, supernova remnants, stars, the Sun and some comets.


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