State some particle properties
- Light travels in straight lines
- Photoelectric effect
- Carrying a charge/mass
- Deflection by an electric or magnetic field
Describe an experiment that showed electrons to behave like a wave
Electron diffraction through graphite - Electrons fired from a cathode so they pass through a graphite target. A series of bright rings can be seen on a phosphorescent screen.
State the evidence that electrons can act like waves
Electrons are being diffracted as they pass through the graphite. Electrons are constructively interfering to produce bright rings. Electrons are destructively interfering to produce dark rings. The same pattern build up with just one electron at a time.
What is the condition required for noticeable diffraction?
For diffraction to be noticeable the wavelength must be similar to the size of the gap it is passing through
Describe the two main methods that cause excitation