If the work function of a material is 2.5 eV, what is the minimum wavelength of

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Question: If the work function of a material is 2.5 eV, what is the minimum wavelength of light required to emit photoelectrons?

Options:

Correct Answer: 500 nm

Solution:

Minimum wavelength (λ) = hc / Φ = (1240 nm·eV) / 2.5 eV = 496 nm.

If the work function of a material is 2.5 eV, what is the minimum wavelength of light required to emit photoelectrons?

If the work function of a material is 2.5 eV, what is the minimum wavelength of light required to emit photoelectrons?

Step 1: Understand the work function (Φ). It is the minimum energy needed to remove an electron from a material. In this case, Φ = 2.5 eV.
Step 2: Know the formula to find the minimum wavelength (λ) of light needed to emit photoelectrons: λ = hc / Φ.
Step 3: Identify the constants: h (Planck's constant) = 4.1357 x 10^-15 eV·s and c (speed of light) = 3 x 10^8 m/s. However, we can use the combined value of hc = 1240 nm·eV for convenience.
Step 4: Plug the values into the formula: λ = (1240 nm·eV) / (2.5 eV).
Step 5: Perform the calculation: λ = 1240 / 2.5 = 496 nm.
Step 6: Conclude that the minimum wavelength of light required to emit photoelectrons is 496 nm.

Photoelectric Effect – The phenomenon where electrons are emitted from a material when it is exposed to light of sufficient energy.
Work Function – The minimum energy required to remove an electron from the surface of a material.
Wavelength-Energy Relationship – The relationship between the energy of a photon and its wavelength, given by the equation E = hc/λ.