some quantum stuff Flashcards
What is all EM radiation(including light) made up of?
Photons
What are photons?
Quanta (packets) of energy
What is the formula for energy of a photon?
E = hf
h=planck’s constant
f=frequency of rotation (frequency of phasor rotation)
What is an alternative form of E=hf using the speed of light,c?
E=hc/λ
What speed do all photons travel at?
the speed of LIGHT
3x10^8 ms^-1
What is the quantum amplitude?
The vector sum of phasors from all possible photon paths to a point
What is quantum probability?
quantum probabiltiy ∝ (quantum amplitude)^2
Why does electron speed vary but photon speed does not?
electrons have MASS
What is the formula for phasor rotation frequancy of electrons?
f = kinetic energy of electrons/h
What is the kinetic energy of electrons accelerated through a voltage,V?
kinetic energy = e x V
e = magnitude of charge on one electron
What is one turn of an electron’s phasor equal to?
one wavelength
What is the formula for finding an electron’s de broglie wavelength?
λ=h/p
p=momentum:
λ=h/mv
What does the LED experiment show?
light energy is emitted in quanta
What data can be plotted to find planck’s constant?
striking voltage against frequency
What is striking voltage?
The minimum voltage needed to produce photons of a certain frequency
