Uses & Dangers of EM Waves

• Where do gamma rays originate from?

  They originate from changes in the nuclei of atoms.
• What health effects can ultraviolet waves cause?

  They can cause the skin to age prematurely. They can increase the risk of developing skin cancer.
• What health effects can x-rays and gamma rays cause?

  They are ionising radiation so can cause mutations in genes. They can lead to increased risk of developing various cancers.
• What health effects can infrared rays cause?

  Infrared waves can cause burns to skin/tissue.
• How does electromagnetic radiation affect electron arrangement in atoms?

  Absorption or emission of electromagnetic radiation can cause electron arrangement to change. (It can remove electrons from the atom or move electrons further from the nucleus).
• How do atoms become ions?

  By losing an outer electron.
• What are the effects of body cells absorbing radiation?

  Large amounts can damage cells. Smaller amounts cause mutation, causing cells to divide rapidly, which can lead to cancer.
• State a use of radio waves.

  Communications, because radio waves are long wavelength and can travel long distances without losing quality.
• State and explain a use of microwaves.

  Cooking, as microwaves are absorbed by and heat fat/water in foods.
• State and explain uses of infrared radiation.

  Cooking food (as it transfers thermal energy) infrared cameras, short range communication.
• State and explain uses of infrared radiation.

  Illuminating (i.e seeing) and fibre optics, as they reflect best in glass (other waves have wavelengths that are too long/short).
• State and explain uses of UV radiation.

  Sterilisation, as it kills bacteria, energy efficient lamps, as it radiates low heat but high energy, and sun tanning etc.
• State and explain uses of x-rays.

  Medical imaging and treatment, because they are very high energy and can easily penetrate body tissues.
• State and explain uses of gamma rays.

  Gamma rays are used in medical treatments, such as radiotherapy in the treatment of cancer.
• Which waves of the EM spectrum are regarded as most dangerous and why?

  Gamma and x-rays, as they have the highest energy.