The Davisson and Germer experiment proved:

What is a wave packet? Explain using a necessary diagram.

Explain Heisenberg's uncertainty principle.

Who made experimental verification of the wave nature of the electron?

The wave property of electrons implies that they will show diffraction effects. Davisson and Germer demonstrated this by diffracting electrons from crystals. The law governing the diffraction from a crystal is obtained by requiring that electron waves reflected from the planes of atoms in a crystal interfere constructively (see figure).

$A$ parallel beam of electrons travelling in $x-$ direction falls on a slit of width $d$. If after passing the slit,an electron acquires momentum $P_y$ in the $y-$ direction,then for a majority of electrons passing through the slit ($h$ is Planck's constant):