Question

A clean surface of chromium ( = 4.40 eV) is struck with ultraviolet radiation with = 1.50 x 10-7 m (a) Determine the speed of the ejected electrons. (b) Determine the de Broglie wavelength of the ejected electrons.

Answer 1

ca) We know, for photcelectric effect - Mass of election - Imv2t0 2 t (work ) ) function Plank's Condant Localy of election Frequency of photos incident (vac the most - 1 m2 - e-he ulky Wavelength of photos incident TC lev= 1.6X10 -19 - 4.400V XI. 6810 I the J) -34 -34 ev -19 34 , Cih= 6.626410 = 34108 m/s) s) 7.04 810 +6.626 X10 IS x 3810 m/s -19 -7.04810 150x10 m ] + 13.252 XIO J 19 6.212 810 J 11:364 x 100 ml - - Imo a 6.212x10-19 ] v = 2 x 6.212x10 h Tim= 9.11x10 kg V 9.11810-31 kg - 1.19x105 mis a har

(b) we know, by De Broglie Equations x=h mv -34 : = 6.626 X 10 JS 9.11x103 kg x 1.17X10 mis = 6.22 x 10 m -10 - 622 x 10 m