When it is struck by 240-nm photons,a metal ejects electrons with a maximum kinetic energy of $2.58 \mathrm { eV }$ What is the work function of this material? (c = 3.00 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s,1 eV = 16.0 × 10^-19 J)

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Quizplus · Accepted Answer

The work function is given by:$$W = hf - KE_{max}$$where:* $h$ is Planck's constant* $f$ is the frequency of the incident photons* $KE_{max}$ is the maximum kinetic energy of the ejected electronsWe can calculate the frequency of the incident photons using the following equation:$$f = \frac{c}{\lambda}$$where:* $c$ is the speed of light* $\lambda$ is the wavelength of the incident photonsSubstituting the given values into the above equations, we get:$$f = \frac{3.00 \times 10^8 \text{ m/s}}{240 \times 10^{-9} \text{ m}} = 1.25 \times 10^{15} \text{ Hz}$$$$W = (6.626 \times 10^{-34} \text{ J s})(1.25 \times 10^{15} \text{ Hz}) - (2.58 \times 16.0 \times 10^{-19} \text{ J})$$$$W = 2.60 \text{ eV}$$Therefore, the work function of the material is 2.60 eV.

When It Is Struck by 240-Nm Photons,a Metal Ejects Electrons 2.58eV2.58 \mathrm { eV }2.58eV

When It Is Struck by 240-Nm Photons,a Metal Ejects Electrons $2.58 \mathrm { eV }$