Properties of waves 2

• Electromagnetic waves


  Waves generated or absorbed when changes take place in atoms or nuclei of atoms
• Generating electromagnetic waves from atoms

  1. Electrons move to higher energy level

  2. Electron returns to original energy level

  3. Electromagnetic wave (e.g. light) is generated
• Generating electromagnetic waves from atomic nuclei

  1. Gamma rays emitted from radioactive atoms

  2. New nucleus has less energy than before
• Electromagnetic waves can also be absorbed by atoms, causing changes like electrons changing energy levels
• Types of electromagnetic radiation

  • Radio waves
  • Ultraviolet waves
  • X-rays
  • Gamma rays
• Ultraviolet waves

  • Increase risk of skin cancer
  • Cause premature skin aging
• 1. rays and gamma rays

  • Ionizing radiation that knocks electrons off atoms
  • Can cause gene mutation and increased cancer risk
• Radiation dose

  Measured in sieverts or millisieverts
• Producing radio waves

  1. Electrons oscillate in an electrical circuit

  2. Radio waves can be absorbed by an aerial, causing electrons to oscillate and create an alternating current