The wave nature of electrons was experimentally verified by,

In the Davisson and Germer experiment,the velocity of electrons emitted from the electron gun can be increased by

Assuming an electron is confined to a $1 \, nm$ wide region,find the uncertainty in momentum using Heisenberg's uncertainty principle. You can assume the uncertainty in position $\Delta x = 1 \, nm$. Assuming $\Delta p = p$,find the energy of the electron in electron volts $(eV)$.

Using the Heisenberg uncertainty principle,arrange the following particles in the order of increasing lowest energy possible.
$(I)$ An electron in $H_{2}$ molecule
$(II)$ $A$ hydrogen atom in a $H_{2}$ molecule
$(III)$ $A$ proton in the carbon nucleus
$(IV)$ $A$ $H_{2}$ molecule within a nanotube

Statement $1$: The Davisson-Germer experiment established the wave nature of electrons. Statement $2$: If electrons possess wave nature,they can undergo interference and diffraction.

Given below are two statements: One is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A:$ The beam of electrons shows wave nature and exhibits interference and diffraction.
Reason $R:$ Davisson-Germer experimentally verified the wave nature of electrons.
In the light of the above statements,choose the most appropriate answer from the options given below: