Question

The work functions for several metals are shown in the table below. If 265 nm light is incident on each of these metals, determine: which metals exhibit the photoelectric effect. Element Chemical Symbol Work Function (EV) 1 Barium Ba 2.48 2 Beryllium Be 3.92 3 Cesium Cs 1.92 4 Gold 4.82 5 Lithium Li 2.35 6 Mercury Hg 4.53 7 Nickel Ni 5.01

Answer 1

- Ang. Wavelength of incident light = d = 265 nm d = 265 x 100 m Energy of single photon of incident light= E 2 ha planck's constant - E= hc 4 ca speed of light / h= 6.63x1034 Jis c= 3x108 mis E = (6.63 x 1034) (3x108) J 2658109 Es 0.075X1027 E= 0.075 x 2017 er 1.6 Xlo 19 E= 4.6875 ev

coevoctquc Occurs photoelectric effect occurs when - Ez work function So, "E" is greater than work function for all the given elements except Gold ( 4-82 eV) and Nickel (5.01 ey) emel L & So answer is option ③