When an electron is accelerated by 2eV, it produces electromagnetic waves (EMW) with a wavelength that can be calculated using the equation E=hc/wavelength. Both electrons and photons exhibit wave properties, and the de Broglie hypothesis applies to moving electrons, allowing for the calculation of their wavelength. When a moving electron stops, it emits a photon, and both the electron and the emitted photon will have the same wavelength if the electron's energy is fully converted to the photon. The relationship between energy and momentum is consistent for both massive particles and EM waves, reinforcing the particle-wave duality concept. Thus, the wavelength of the electron and the wavelength of the EMW produced are indeed the same when energy is conserved.