> The current understanding is that since electrons are quantum particles, they can only gain or lose energy through quantized packets Just to clarify. An elec

> The current understanding is that since electrons are quantum particles, they can only gain or lose energy through quantized packets Just to clarify. An electron moving freely through a vacuum can move at any speed; it is not restricted to certain energy levels. (Speed and therefore kinetic energy is relative to the reference frame anyway.) The quantization of energy comes into play when the electron is spatially confined in some system. This is related to the wave behavior of the particle, and because energy is related to wavelength. Much like how a standing wave on a string can only have wavelengths such that an integer multiple of them fit on the string.