R-ATPHY-32

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de Broglie wavelength intro

There is a wave-particle duality for most things, which means all things have a wavelength of sorts, even you!!!!

This resulted in many experiments, such as the double slit experiment for electrons.

Gold foil question:

Electrons behave as waves
When hit gold they can thus produce diffraction pattern
This has max and min due to constructive and destructive interference as shown in image

Tada!

de Broglie wavelength (real stuff)

Light behaves as waves or particle...
Matter behaves as waves or particles?
e.g. electrons -
- Significant mass (I guess), usually described as particles.
- However, they can produce interference patterns with an electron beam. This is wave behaviour, not particle behaviour!
de Broglie wavelength:
- Gives a wavelength to a particle with significant mass.

$$\begin{align} \lambda=\frac{h}{mv}=\frac{h}{p} \\ (p=mv) \end{align} $$

e.g.

$$\begin{align} \lambda&=\frac{6.63\times 10^{-34}}{9.11 \times 10^{-31}\times 10^6} \\ &=7.27\times 10^ {-10}m \end{align} $$\ Thus, an electron moving at $10^6ms^{-1}$ has a wavelength of $7.27\times 10^{-10}$. Notice this is much smaller than visible light. This small wavelength is apparently useful in the electron microscope, as they can interact with much smaller particles than visible light(better compared to conventional light microscopes). $$

R-ATPHY-32

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de Broglie wavelength intro

de Broglie wavelength (real stuff)

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