Photoelectric Effect

Question 1

Ultraviolet catastrophe and black body radiation

Answer 1

All objects emit EM radiation due to their temperature.

Pure black surfaces emit radiation in accordance with the black body radiation curve

Classical wave theory could not explain the graph

Question 2

What is a Black Body?

Answer 2

Absorbs all wavelengths of EM radiation and can emit all wavelengths.

Question 3

How did Max Planck Explain the graph?

Answer 3

suggested that EM waves can only be released in quanta

Question 4

Einsteins Explanation of PE

Answer 4

Electron interact with photons that strike the surface. If energy is greater than work function then photon is emitted; it is a 1to1 interaction.

Whether an electron is emitted depends on the photons frequency.

WF is minimum energy needed for an electron to be released.

Einsteins work shows that light is made from particles of light (photons)