Editing Diffraction (section)

== Matter wave diffraction ==
{{see also|Matter wave|Neutron diffraction|Electron diffraction}}
According to quantum theory every particle exhibits wave properties and can therefore diffract. Diffraction of electrons and neutrons is one of the powerful arguments in favor of quantum mechanics. The wavelength associated with a non-relativistic particle is the [[de Broglie wavelength]]
<math display="block">\lambda=\frac{h}{p} \, ,</math>
where <math>h</math> is the [[Planck constant]] and <math>p</math> is the [[momentum]] of the particle (mass × velocity for slow-moving particles). For example, a sodium atom traveling at about 300&nbsp;m/s would have a de Broglie wavelength of about 50 picometres.
 
Diffraction of [[matter wave]]s has been observed for small particles, like electrons, neutrons, atoms, and even large molecules. The short wavelength of these matter waves makes them ideally suited to study the atomic structure of solids, molecules and proteins.