Dual Nature of Radiation and Matter Summary

• The phenomenon of interference, diffraction and polarization can be explained by the wave theory of light.

• But the photo electric effect can be explained only using 'photon theory'. That is using particle nature of light.

• The experimental study of photoelectric effect led to the concepts of threshold frequency and cut-off voltage (Stopping potential) and ultimately Einstein gave the photoelectric equation.

-EV₀ = hu - hu₀

Where V₀ - stopping potential

- u₀ - threshold frequency.

• A photocell is one, which converts the changes in the intensity of light into changes in the electric current. Photoconductive cells and photoelectric cells find their use in television camera, burglar alarm, in counting devices etc.

• Light shows dual nature sometimes manifesting itself in the form of waves and sometimes in the form of particles.

• Similar to light, matter also manifests itself in the form of particles as well as waves. Compton effect, and Davison and Germer's experiment stand as evidence for dual nature of matter.

• If an electron acts as a wave, its wavelength is calculated to be

  

• Davison and Germer showed the electron diffraction can be explained with Bragg's formula 2dSinq = nl showing the similarity between X-ray diffraction and electron diffraction.

An electron microscope is found to have better magnification and resolving power compared to the optical microscope.