Threshold Frequency Calculation: 3.33eV Work Function

In summary, threshold frequency is the minimum frequency of light required to eject an electron from a metal surface, determined by the work function of the metal. It is calculated using the formula f<sub>0</sub> = W/h, with 3.33eV often used as a standard value. Work function is the minimum energy required to remove an electron from a metal surface, measured in eV. The photoelectric effect is the emission of electrons from a metal surface when exposed to light, with threshold frequency being the minimum frequency required for this effect to occur.
  • #1
harhar
22
0
How would I find the threshold frequency if the work function is 3.33eV?
I know how to calculate minimum frequency.
 
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  • #2
[tex] K = \phi - hf_0 [/tex]
where K is K.E.
Now K>0
therefore threshold frequency will be when K=0
 
  • #3


To find the threshold frequency, you can use the equation E = hf, where E is the energy (in electron volts, eV), h is Planck's constant (4.1357 × 10^-15 eV·s), and f is the frequency (in hertz, Hz).

Since the work function is given in eV, you can convert it to joules by multiplying it by the conversion factor 1.6022 × 10^-19. This gives a work function of 5.33 × 10^-19 J.

To find the threshold frequency, you need to first calculate the energy required to overcome the work function. This can be done by subtracting the work function from the energy of an electron, which is 0.511 MeV (million electron volts).

So, the energy required would be 0.511 MeV - 3.33 eV = 0.50767 MeV.

Now, you can plug this energy into the equation E = hf and solve for f.

0.50767 MeV = (4.1357 × 10^-15 eV·s) f

Solving for f, you get a threshold frequency of 1.226 × 10^21 Hz.

To find the minimum frequency, you can simply divide the threshold frequency by 2π, as the minimum frequency is equal to the threshold frequency divided by 2π.

So, the minimum frequency would be 1.226 × 10^21 Hz / 2π = 1.951 × 10^20 Hz.

In summary, to find the threshold frequency when the work function is 3.33eV, you would first convert the work function to joules, subtract it from the energy of an electron, and then solve for the frequency using the equation E = hf. This would give you a threshold frequency of 1.226 × 10^21 Hz. The minimum frequency can be found by dividing the threshold frequency by 2π, giving a value of 1.951 × 10^20 Hz.
 

1. What is threshold frequency?

Threshold frequency is the minimum frequency of light required to eject an electron from a metal surface. It is determined by the work function of the metal.

2. How is threshold frequency calculated?

Threshold frequency is calculated using the formula f0 = W/h, where f0 is the threshold frequency, W is the work function, and h is Planck's constant.

3. What is the significance of 3.33eV in threshold frequency calculation?

3.33eV is the approximate work function of most metals. It is used as a standard value in the calculation of threshold frequency.

4. Can you explain the concept of work function?

Work function is the minimum amount of energy required to remove an electron from the surface of a metal. It is measured in electron volts (eV) and is unique to each metal.

5. How does threshold frequency relate to the photoelectric effect?

The photoelectric effect is the emission of electrons from a metal surface when exposed to light of sufficient energy. Threshold frequency is the minimum frequency of light required for this effect to occur. If the frequency of the light is below the threshold frequency, no electrons will be emitted regardless of the intensity of the light.

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