In the double slit experiment, under observation, the electron acts like a particle rather than a wave. From my understanding this is because the photon that hits it for observational purposes adds enough energy into the system to affect the electron and make it chose one single path rather than both (broken telephone here, so please correct me where I'm wrong). So I have two questions, first, why does this extra energy cause the electron to change from a wave to a particle? And secondly, what "ideal" conditions are required for this experiment? Because in a normal lit room in everyday situations, aren't photons always hitting electrons? Thus wouldn't they all end up acting like particles rather than waves?