If the work function of a metal is 2.5 eV, what is the minimum wavelength of light required to emit photoelectrons?
Practice Questions
1 question
Q1
If the work function of a metal is 2.5 eV, what is the minimum wavelength of light required to emit photoelectrons?
400 nm
500 nm
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700 nm
Minimum wavelength (λ) = hc / Φ = (1240 nm·eV) / 2.5 eV = 496 nm.
Questions & Step-by-step Solutions
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Q
Q: If the work function of a metal is 2.5 eV, what is the minimum wavelength of light required to emit photoelectrons?
Solution: Minimum wavelength (λ) = hc / Φ = (1240 nm·eV) / 2.5 eV = 496 nm.
Steps: 6
Step 1: Understand the work function (Φ) of the metal, which is given as 2.5 eV. This is the minimum energy needed to release photoelectrons.
Step 2: Use the formula to find the minimum wavelength (λ) of light required 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: Substitute the values into the formula: λ = 1240 nm·eV / 2.5 eV.
