For this part of the experiment, we will be examining the effects of changing the applied voltage on the number of electrons emitted, and determining if that changes based on the wavelength of the light. To set this up, first reset the simulation to the original settings. Use the controls to set the voltage to zero. Turn up the brightness to its maximum setting. Make sure that you have reset the metal back to potassium. ● 13. For potassium, we are going to determine the applied voltage at which NO electrons are detected, as a function of the wavelength of light that is shining on the metal. To do this, you will ● first set the wavelength of light shining on the potassium surface next, slowly increase the voltage applied. You will have found the "stopping voltage" when the photoelectrons emitted from the potassium surface do not quite reach the detector, so that no currer at all is detected. Then you will calculate the frequency of the photons, and from there, use the frequency to calculate the photon energy in eV. Wavelength (nm) 200 nm 250 nm 300 nm 350 nm 400 nm Stopping voltage (Volts) Frequency (Hz) Photon energy (eV) 4.0V 2.7V 1.9V 1.3V 0.8V

For this part of the experiment, we will be examining the effects of changing the applied voltage on the number of electrons emitted, and determining if that changes based on the wavelength of the light. To set this up, first reset the simulation to the original settings. Use the controls to set the voltage to zero. Turn up the brightness to its maximum setting. Make sure that you have reset the metal back to potassium. ● 13. For potassium, we are going to determine the applied voltage at which NO electrons are detected, as a function of the wavelength of light that is shining on the metal. To do this, you will ● first set the wavelength of light shining on the potassium surface next, slowly increase the voltage applied. You will have found the "stopping voltage" when the photoelectrons emitted from the potassium surface do not quite reach the detector, so that no currer at all is detected. Then you will calculate the frequency of the photons, and from there, use the frequency to calculate the photon energy in eV. Wavelength (nm) 200 nm 250 nm 300 nm 350 nm 400 nm Stopping voltage (Volts) Frequency (Hz) Photon energy (eV) 4.0V 2.7V 1.9V 1.3V 0.8V