Mention the significance of Davisson-Germer experiment. An `alpha`-particle and a proton are accelerated from rest through the same potential difference `V`. Find the ratio of de-Broglie wavelengths associated with them.

Explanation

Davisson-Germer experiment establishers the existence of matter waves. `K.E`. Gained by a charged particle when accelerated `V` volts is:
`K=(1)/(2)mv^(2)=qv`
`:. v=sqrt((2qv)/(m))`
de-Broglie wavelength of the particle,
`lambda=(h)/(mv)=(h)/(msqrt((2qV)/(m)))=(h)/(sqrt(2mqv))`
For same `V`,
`(lambda(alpha-"particle"))/(lambda("proton"))=sqrt((m_(p)q_(p))/(m_(alpha)q_(alpha)))=sqrt((m_(p)e)/(4m_(p).2e))=(1)/(sqrt(8))=(1)/(2sqrt(2))`