$G$ $P$ Thomson experimentally confirmed the existence of matter waves by the phenomenon of:

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 $(eV)$.

An electron behaves like a wave because it......

Explain Heisenberg's uncertainty principle.

$A$ 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):

$A$ sodium atom is in one of the states labeled 'Lowest excited levels'. It remains in that state for an average time of $10^{-8} \, s$,before it makes a transition back to a ground state. What is the uncertainty in energy of that excited state?