posted by Alphonse .
Observing electron interference through an ordinary macroscopic two-slit experiment would be extremely difficult and would require very slowly moving electrons. (Slow for an electron means < 10^3 m/s.)
How slowly would electrons have to move through slits spaced 6.53 Î¼m apart in order for the first angular displacement from the central interference maximum to where we observe no electrons to be 12.3 degrees? (Answer in m/s.)