Photoelectric effect: In a photoelectric effect experiment, electrons emerge from a copper surface with a maximum kinetic energy of 1.10 eV when light shines on the surface. The work function of copper is 4.65 eV. Which one of the following values is closest to the wavelength of the light? (h = 6.626 × 10^-34 J ∙ s, c = 3.00 × 10⁸ m/s, 1 eV = 1.60 × 10^-19 J) A) 220 nm B) 150 nm C) 360 nm D) 1100 nm

Question

Quizplus · Accepted Answer

Using the formula $E_{max} = \frac{hc}{\lambda}-\phi$, where $h$ is Planck's constant, $c$ is the speed of light, $\lambda$ is the wavelength of the light, and $\phi$ is the work function, we can solve for $\lambda$:
$\lambda = \frac{hc}{E_{max}+\phi}$
Plugging in the given values:
$\lambda = \frac{(6.626 	imes 10^{-34} J \cdot s)(3.00 	imes 10^{8} m/s)}{(1.10 	imes 1.60 	imes 10^{-19} J) + (4.65 	imes 1.60 	imes 10^{-19} J)} \approx 220 	ext{ nm}$
Therefore, the best choice is A.

Photoelectric Effect: in a Photoelectric Effect Experiment, Electrons Emerge from a Copper