18-1

What is the threshold frequency 0 of cesium? Express your answer numerically in hertz. Correct Correct answer is shown. Your answer 5.21014=5.21014Hz was either rounded differently or used a different number of significant figures than required for this part Important: If you use this answer in later parts, use the full unrounded value in your calculations. Part B A ray of yellow light has a wavelength of about 5.80107m. Will exposure to yellow light cause electrons to be emitted from cesium? View Available Hint(s) Correct The energy of yelow light with a wavelength of about 5.80107m is equal to E=hc/. E=hc=5.80107m(6.631034Js)(2.99108sm)=3.431019J Part C What is the kinetic energy of the emitted electrons when cesium is exposed to UV rays of frequency 1.301015Hz ? Express your answer in joules to three significant figures. X Incorrect; Try Again; 19 attempts remaining