EMR

• What is the interrelation of electric and magnetic fields called?

  Electromagnetic
• What does radiation refer to?

  Emission/transmission of radiant energy
• In what forms can radiation exist?

  Waves, particles, or sound
• How is electromagnetic radiation (EMR) defined?

  As a wave of electric and magnetic energy
• What causes a varying magnetic field in EMR?

  Varying motion of charge
• How are electric and magnetic fields oriented in EMR?

  They are perpendicular to one another
• In what direction do the fields of EMR travel?

  At right angles to one another sinusoidally
• What is the most common form of EMR?

  Light
• How is each type of EMR distinguished?

  By its wavelength
• What does arranging EMR by wavelength produce?

  The electromagnetic spectrum
• What types of waves are included in the electromagnetic spectrum?

  Radio waves, microwaves, infrared, visible light, UV light, x-rays, gamma rays
• Which EMR has the longest wavelength?

  Radio waves
• Which EMR has the shortest wavelength?

  Gamma rays
• What is the wave-particle duality of EMR?

  EMR is considered both a wave and a particle
• Who first described light as a wave?

  Robert Hooke
• What did Isaac Newton argue about light?

  That light acts like a particle
• What principle did Christian Huygens discover?

  Principles of refraction and interference
• Who confirmed Hooke's theory that light was a wave?

  Thomas Young
• What did James Clerk Maxwell introduce?

  The concept of electromagnetism
• What did Heinrich Hertz observe in his experiments?

  Emission of electrons from metals by light
• What concept did Max Planck introduce?

  Planck's constant
• What did Einstein propose about light?

  That light must have particles of energy
• What did Louis de Broglie hypothesize about light particles?

  They must be concentrations of energy in a wave
• What does quantum mechanics propose about light?

  That light is both a wave and a particle
• How do electric and magnetic fields travel in the wave model?

  Perpendicular to one another in a sinusoidal manner
• What is wavelength (λ)?

  The distance to complete one cycle
• What is frequency (f) in relation to wavelength?

  Inversely related to wavelength
• What is the formula for the velocity of a wave?

  c = λ f
• What happens to EMR with high frequency?

  It has short wavelength and high energy
• What happens to EMR with low frequency?

  It has long wavelength and low energy
• What is absorption in the context of EMR?

  Particles of energy that can be absorbed
• What are photons in relation to EMR?

  Particles of energy in EMR
• What phenomenon can reflection be explained by?

  Both wave and particle models
• How does reflection occur in the wave model?

  Change in direction at an interface
• How does reflection occur in the particle model?

  Particles lose energy and change direction
• How does refraction occur in the wave model?

  Wave strikes a medium at an angle
• How does refraction occur in the particle model?

  Particles lose energy and change direction
• What is interference in wave phenomena?

  When two waves reinforce or cancel each other
• What is constructive interference?

  When two waves reinforce one another
• What is destructive interference?

  When two waves cancel one another