Presentation on theme: "Ch. 18 – The Electromagnetic Spectrum"— Presentation transcript:
1 Ch. 18 – The Electromagnetic Spectrum I. Electromagnetic RadiationEM RadiationEM SpectrumTypes of EM Radiation
2 A. EM Radiation Electromagnetic Radiation transverse waves produced by the motion of electrically charged particlesdoes not require a mediumspeed in a vacuum = 300,000 km/selectric and magnetic components are perpendicular
3 B. EM Spectrumlong low flow energyshort high fhigh energy
4 C. Types of EM RadiationRadiowaveslowest energy EM radiation
5 C. Types of EM Radiation Radiowaves FM - frequency modulation AM - amplitude modulationMicrowavespenetrate food and vibrate water & fat molecules to produce thermal energy
6 C. Types of EM Radiation Infrared Radiation (IR) slightly lower energy than visible lightcan raise the thermal energy of objectsthermogram - image made by detecting IR radiation
7 C. Types of EM Radiation Visible Light small part of the spectrum we can seeROY G. BIV - colors in order of increasing energyROYG.BIVredorangeyellowgreenblueindigoviolet
8 C. Types of EM Radiation Ultraviolet Radiation (UV) slightly higher energy than visible lightTypes:UVA - tanning, wrinklesUVB - sunburn, cancerUVC - most harmful, sterilization
9 C. Types of EM Radiation Ultraviolet Radiation (UV) Ozone layer depletion = UV exposure!
10 C. Types of EM Radiation X rays higher energy than UV can penetrate soft tissue, but not bones
11 Radiation treatment using radioactive cobalt-60. C. Types of EM RadiationGamma rayshighest energy EM radiationemitted by radioactive atomsused to kill cancerous cellsRadiation treatment using radioactive cobalt-60.