Question

The following data gives stopping potential Vo versus wavelength for photoelectrons produced from a metal surface. (Be sure to include the correct units and use three significant figures.) Table 1 Vo (nm) (volts) 50 100 9.33 150 5.19 2003.15 2501.86 300 1.05 21.4 Use an analysis similar to that used in the inlab procedure to determine the work function (in ev) for this surface. (Use1 ev -1.602 x 10-19j, e- 1.602 x 10-19 c,2.998 x 108 m/s, and h . 6.626 × 10-34 , . s-4.136 x 10-15 ev . s as necessary.) Enter a number with the correct number of significant fiqures

Answer 1

The photoelectric effect equation is that the energy of the incident photon is equal to the sum of the kinetic energy of the ejected electrons and the work function of the photo metal. E-W+K The kinetic energy of the electron is equal to the energy needed to stop them by using the stopping potential Therefore, Compare this equation with the straight line equation y-mx+c. The y-interception is equal to The frequency of the radiation is equal to the speed of the light divided by the wavelengtlh The table below represents the stopping potential versus frequency|

Plot a graph by taking the value of stopping potential on y-axis and the frequency on x- axis. 25 y4.0721x-2.973 20 10 0 0 1 4 6 7 Frequency (x10*15 Hz) The straight line equation is, y 4.0721x-2.9733 Therefore, the y-interception is - 2.9733 W (2.9733 V)(e) (2.9733 v)(e) - 2.9733 eV Therefore, the stopping potential is 2.9733 eV.