26.1 Blackbody Radiation, Photoelectric Effect, and de Broglie Relation
Blackbody Radiation, Photoelectric Effect, and de Broglie Relation
Blackbody Radiation
• Classical Theory matches observed intensities at long wavelengths
• Ultraviolet Catastrophe – classical theory predicts that the intensity should approach infinity as the wavelength approaches zero
• Planck proposed a model of quantized resonators (oscillators) having discrete energies (En = nhf)
Photoelectric Effect
• Wave-Particle Duality of Light
λ f = c
• Light exhibits particle-like characteristics (photon).
• Light is quantized having discrete energies.
E = h f = h c / λ h = 6.626×10-34J • s
p = h / λ p = momenturm
• 1 electron can be emitted per photon.
KEmax = h f - ɸ ɸ = work function
de Broglie Relation (Wave Behavior of Matter)
λ = h / m v λ = wavelength h = 6.626×10-34J • s m = mass v = velocity