Light Wave or Particle?

Evidence Wave Properties Particle Properties

Interference of Light When two light waves hit they _______________________________ each other. While they occupy the same space the waves _______ amplitudes and frequencies to produce a different wave. This is called _______________________. If two _________ hit they bounce off each other. They don’t interfere like waves.

Refraction & Dispersion of Light When light enters glass it _________. This is called ____________ How much light refracts depends on the type of _____ and the ____ of light. A particle could refract, wave theory works better. When _________ light enters glass the different frequencies bend differently. This causes the light to split into the ____________. This is called ______________. Particles wouldn’t display dispersion.

The Doppler Effect for Light When a light source is moving the frequency of light it emits changes due to this _____________. A particle doesn’t do this, only a _____________.

Diffraction of Light You get a _________________, called a _______________________ pattern. Basically the light __________ as it _________ the slit causing an alternating series of constructive and destructive interference. A particle wouldn’t do this. If I fire this laser through a small slit, what will I see on the wall when it hits?

The Photoelectric Effect When light hits certain metals it causes the metal to eject ______________. Treating light as a wave tells us that the __________ the light, the more electrons get ejected or the electrons get ejected at a ________________. This would be true if it wasn’t__________!!! It turns out the ______________ of the light is what determines whether or not electrons are ____________ from the metal. This suggests that light travels in _________ or packets called _______ which behave like particles.

The Ultraviolet Catastrophe A blackbody radiator absorbs all electromagnetic radiation that hits it and emits its own electromagnetic radiation based on its ___________. Wave theories predict that the wavelengths of electromagnetic waves a blackbody will emit should follow the relationship shown by the ___________________ in the graph. It turns out that experiments show that the wavelength of electromagnetic waves emitted by a blackbody actually follow the ______________ shown in the graph called blackbody curves. Which curve is determined by the temperature of the blackbody.

The Ultraviolet Catastrophe This also suggests that light travels in _______ or packets called ______ which behave like ________.

The dual nature of light