Question

Quantum Physics - Photoelectric Effect 1 Light Light2 Photo- electrons KEL KEN-W Photoelectric Effect Lenard found that light has to be above a certain frequency in order to observe photoelectrons The Planck constant is 6.626x10^-34 J s. The calcium metal has a work function WO = 2.71 eV, 1eV = 1.6x10^-19). (a) What is the Cutoff frequency for the calcium metal? Write the result in terms of 1014Hz. Keep 3 decimal places. Enter a number x1024Hz Submit (5 attempts remaining) What is the longest wavelength of incident light in order to emit photoelectrons from the calcium metal? Write wavelength in nm, 1nm = 109 m. Keep 2 decimal places. Enter a number nm Submit (5 attempts remaining) Case 1: An incident light with a wavelength = 398.64 nm shines on the calcium metal. (b) Will electrons be emitted from the calcium metal? Select your answer from one of the following options. a. No, because the incident photon frequency is smaller than the cutoff frequency. b. No, because the incident photon wavelength is larger than the longest wavelength. • C. Yes, because the incident photon frequency is larger than the cutoff frequency. d. Yes, because the incident photon wavelength is larger than the longest wavelength. Correct (100.0%) Submit (c) Calculate the energy carried by the photons in the incident light Write the result in terms of 10 -19 J. Keep 3 decimal places. Enter a number x10-19 Submit (5 attempts remaining) (d) Calculate the max kinetic energy carried by the photo-electrons Write the result in terms of 10-19). Keep 3 decimal places. Enter a number x10-19, Submit (5 attempts remaining)

Answer 1

given constant ecole function of Galerium, wo: 2.12 ev plancha 34 ha 6.626 X10 Je dev = 1,6x1093 1 The wosh funchen se goven by Wohlo ewhere, to as the autoff so, call off frequency, it fo frequency of the calcium, melod 9,71 er 271 * 1.6110192 h 6.646X10945.5 fo- = 6.5459 XI0 6.626 X 1034 J.S Hz to = 6.5439x10' 14 HZ (fo = 6.544810 Hz 14 The given by Cuplo 3 decimal places, longest comedongle of the en anded light in orchen to emit photoelectrons from the calcium metal they offe - (9x10* mm (6.5448101447) 458.44 x 109m os C Cubo dan X long = 458.44 0002 we in [Along (6 If incident a light of womelength = 398, 6h non, then, Yes, the electrons will be emitted from the calcrum motel because, an adent photo frequeng a larger than the custoff option. "C" as, incident frequeny d= 7 frequency, 3x108 m/s 14 7.526 810 HZ 398.64X100