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)

Question

Quizplus · Accepted Answer

The energy of the incident light is the sum of the work function and the maximum kinetic energy of the electrons: $E = \phi + K_{max}$, where $\phi = 4.65 \, \text{eV}$ (work function) and $K_{max} = 1.10 \, \text{eV}$ (maximum kinetic energy). Converting eV to Joules, $E = (4.65 \, \text{eV} + 1.10 \, \text{eV}) \times 1.60 \times 10^{-19} \, \text{J/eV}$. The wavelength $\lambda$ can be found using the equation $E = \frac{hc}{\lambda}$, where $h = 6.626 \times 10^{-34} \, \text{J} \cdot \text{s}$ and $c = 3.00 \times 10^8 \, \text{m/s}$. Solving for $\lambda$ gives a value close to 220 nm.

In a Photoelectric Effect Experiment,electrons Emerge from a Copper Surface