Wave-particle duality, spectra
- The diffraction of electrons by graphite shows that they have wave properties. Diffraction of electrons can show the size of a nucleus.
- De Broglie equation: The wavelength of the wave motion associated with a moving particle of momentum mv is λ = h/mv
- The line spectrum from a gaseous-discharge lamp provides evidence of discrete energy levels for the electrons in an atom.
- If an electron falls from energy level E1 to energy level E2, then a photon of frequency f is emitted, where hf = E1 − E2