Ch 30 Quantum Physics

CH 30 Quantum Physics Subject

Relevant Equations Wien's Displacement Law: ƒpeak= (5.88 x 1010s-1•L-1)T S.I.=Hz =s1

Quantized Energy: En=nhf n=0,1,2,3… & Planck's Constant, h: h=6.63 x 10-34 J•s S.I. = J •s Energy of a Photon with Frequency, ƒ E=hƒ S.I= J Work function, Φ : Kmax=E-W0 Photons and Cutoff Frequency: the ƒ0=W0/h Photoelectric S.I= Hz = s-1 Effect Kmax= hƒ-W0 Rest Mass of a Photon: m0=0 Momentum of Photon: Mass/Moment p= (hf/c) = (h/λ) also um of Photon (E/c) Compton Shift Formula: Δλ=λ'-λ =(h/mec)(1-cosΘ) S.I.= m Compton wavelength of an electron, (h/mec) Compton = Effect: 2.43 x 10-12 m Blackbody Radiation Planck's Theory

Relationships blackbody: a system that gives off electromagnetic radiation. An ideal blackbody absorbs all the light that is incident on it. •Distribution of energy on the blackbody is NOT dependent on the material. •It is ONLY affected by temperature. •Direct connection between temperature of an object and the frequency of radiation it emits strongly.

photons: bundles of energy work function: minimum amount of energy necessary to eject an electron from a particular metal cutoff frequency: the minimum frequency to eject electrons. If cutoff frequency is not reached, intensity will have no effect on electron emission.

•Energy Conservation: energy of incident photon=energy of scattered photon + final kinetic energy of electron. •Light can exhibit particle like behavior, then an electron, should exhibit wave like behavior. •The greater the particle's momentum, the de Broglie Wavelength: smaller the de Broglie wavelength. λ= (h/p) •If the difference in path lengths is ½ a lambda, S.I.= m then destructive interference occurs. If the Diffraction of X-rays difference is 1λ, then constructive interference de Broglie and particles by occurs. Hypothesis & Crystals: Wave-particle duality: Light having particle like Wave-Particle 2dsinΘ =mλ properties and particles exhibiting wave like Duality m=1,2,3... properties Dark Fringe: sinΘ=λ/W Momentum and Position: ΔpyΔy ≥ h/2π Heisenberg Energy and Time: Uncertainty •It is impossible to predict exactly where that one Principle ΔEΔt ≥ h/2π electron will land on the screen.