1 / 11

Quantum Physics

Quantum Physics. ….and you thought I couldn’t use Powerpoint. BlackBody Radiation. ALL objects radiate thermal energy based on the vibration of the atoms within the molecules Cold in the IR range – not visible Turn up the heat & radiation becomes visible

carl
Download Presentation

Quantum Physics

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Quantum Physics ….and you thought I couldn’t use Powerpoint

  2. BlackBody Radiation • ALL objects radiate thermal energy based on the vibration of the atoms within the molecules • Cold in the IR range – not visible • Turn up the heat & radiation becomes visible • ROYGBIV (red hot toaster or stove burner, white light bulb filament) • Big l to Short l or • Low f to high f

  3. Black-Body Experiment

  4. Black Body Problem

  5. Planck’s Thinking

  6. Planck-Thermodynamics • Says we get the graphs because atomic oscillators’ are only able to oscillate at distinct frequencies: E=nhf Compare to a box being pushed up an incline or lifted up individual steps. In the first case the GPE increases continuously in the second in increments. • The oscillators produce the em wave.

  7. Photoelectric Effect (Einstein’s Nobel Prize)

  8. Photoelectric Effect Problem: Wave versus Particle • Any f should remove electrons . Not Observed. • Intensity   Energy Regardless of f • Emitted e- energy should depend on Intensity of light beam. Not Observed. • Emitted energy depends on f • Waves of light spread energy across metal. Requires time for e- to absorb energy and fly off. Not Observed.

  9. Light & Einstein Light is a PARTICLE • Einstein: light has no mass, but DOES have KE • Einstein predicted light waves have p! • Had no way of confirming these formulas

  10. Ephoton=hf KEmax=KEelectronf=work function Stopping Voltage used to find Kemax: Ue=KEmax KEmax=hf-f

  11. Photoelectric Effect Graph • y=mx+b • Threshold Frequency = x-intercept • Work Function = y-intercept • Planck’s Constant = slope

More Related