2.5/2.6 - Quantum physics and wave particle duality

Photon energy equation

E = hf

Define work function

minimum energy to release e- from metal surface

Photoelectric equation words

energy of incoming photon = energy to escape + left over energy

Photoelectric equation letters

hf = 1/2mv² + hf0

Energy level equation

hf = energy difference between levels

Define threshold frequency

minimum frequency to release photoelectron

Laser action

population inversion causes stimulated emission in metastable state making coherent light

X-ray production

high speed e- decelerate hitting metal target, lose KE emitted as X-rays

de Broglie equation

wavelength = h / p

Evidence light is a wave

diffraction and interference

Evidence light is a particle

photoelectric effect

Electron diffraction

e- diffract through crystal lattice so have water properties

Define photon

packet of EM energy

Alternative unit of energy

electron volt

Energy levels

e- in energy levels in atoms so only occupy certain energies

Emission line spectra

produced when e- drop to lower energy levels emitting photons of specific frequencies

Define wave particle duality

EM radiation behaves as wave and particle

CT scanning vs conventional X-ray - what it makes and use. Also method for CT scanning

X-ray makes 2D image, bone; CT scan rotates X-ray beam around patient making 3D image, soft tissues

Photoelectric effect experiment

UV light directed at zinc plate on gold leaf electroscope, leaf falls as e- emitted from zinc, no emission with normal light so frequency determines emission

Why wave model fails to explain photoelectric effect

predicts frequency with enough intensity releases e-, but below threshold frequency no emission regardless of intensity