Quantum Physics Flashcards
Single slit experiment: expect with particles
Zero hits in shadow region
Single slit experiment particle: observed
Particles hit shadow region
F=ma failed
Single slit experiment: large p affects spread how
Smaller spread
Single slit experiment: large wavelength affects spread how?
Larger spread
Double slit: expect
One big interference pattern (one large bump)
Double slit: observe
Many lumps (like a sin wave lol) P = P1 + P2 + interference terms
Photoelectric effect: wave (3)
1) happens for any f provided A^2t is large enough
2) need A^2t > w, measurable time delay
3) kmax proportional to A^2, more intense light increases Kmax
All wrong
Photoelectric effect: particle (3)
1) minimum threshold frequency indep of A, t
2) instantaneous (particle collision)
3) completely indep of light intensity
How is all light created
Accelerated electric charge
X-Ray production: wave
Light of all frequencies produced
Wrong
X-Ray production: particle
Only light with f less than F max produced
Why do you have an atomic nucleus in pair production
For momentum conservation
If not, how can two particles momentum = c?
Chemical reaction energy is about
1eV
Nuclear reaction energy is about
1 MeV
Blackbody radiation
Closed box at T, atoms vibrate emitting EM waves in thermal equilibrium
Waves can be thought of as superposition of many em standing waves with random fluctuating amplitude and phase, maintain thermal eq via walls
Ultraviolet catastrophe
Wave model fails
Frequency should just continue to go up with more intensity and stuff, but it doesn’t be particle
Static model of the atom
Electrostatic forces hold it together
Problems with the static model
The attractive force would cause acceleration and electron would lose em waves as energy and collapse
Dynamic model of the atom
Like planets orbiting sun
Problems with dynamic model
Same as static - centripetal acceleration is still acceleration
Now they have a fun spiral
Why doesn’t electron cloud exist
Electrostatic repulsion of parts of electron would change energy levels in not observed ways
Instead electron is point particle that behaves like wave
How does the stationary state fix the atom problem
Rotating ring of charge instead of point charge
Creates steady current loop and magnetic field instead
