Photoelectricity Flashcards
How does UV light affect the gold leaf electroscope?
UV light dissipates the negative charge, meaning the gold leaf moves back to its original position. Increasing the intensity of the UV light makes the whole process faster.
Why can’t red light dissipate the electrons?
It doesn’t have a high enough energy.
What is the threshold Frequency?
The minimum frequency of a photon needed to remove an electron from one metal
When can an electron leave the metal surface?
When the energy gained from a single photon exceeds the work function
What is the fmin or the fo of a graph?
The minimum frequency to get electrons removed - threshold frequency
What is the gradient of a photoelectricity graph and how does it change for each metal?
h = 6.63x10^-34
Same for every metal
Where does the graph intercept the y axis? (The name of the value)
Work function
What is the stopping potential?
The minimum potential needed to stop photoelectric emission.
What is the work function?
The minimum energy needed by an electron to escape from the metal surface
What is the threshold frequency?
The minimum frequency of a photon needed to remove an electron from one metal
How do you get the photoelectricity graph?
Changing the frequency of the light and reading the voltmeter
