Science Homework Help

Choose the right answer from options below

A photoelectric experiment was performed by shining a 250 nm laser on a metal surface.

Conversion factor: 1 eV = 1.6022 x 10-19 J;

Mass of electron: me = 9.10938356 × 10-31 kg

Speed of light: c = 3.00 x 108 m/s ;

Plank constant: = 6.62607004 × 10-34 m2 kg s-1

Formula: Ephoton = ? + KEe = h ?0 + ½ me ?2

If the metal is cadmium, Cd, with work function ? = 4.07 eV, what is the kinetic energy KEe (J) and velocity ? (m/s) of the electrons emitted? 

KEe =                  [ Select ]                          [“7.89 x 10^(-17) J”, “1.43 x 10^(–19) J”, “6.52 x 10^(–19) J”, “1.45 x 10^(-18) J”]            , 

? =                  [ Select ]                          [“5.60 x 10^5 m/s”, “1.32 x 10^7 m/s”, “1.78 x 10^6 m/s”, “1.20 x 10^6 m/s”]            

What is the maximum number of electrons that can be emitted in the experiment above if the metal surface absorbs 3.25 x 10–3 J of radiation?                  [ Select ]                          [“6.38 x 10^15 electrons”, “4.98 x 10^15 electrons”, “2.27 x 10^16 electrons”, “4.09 x 10^15 electrons”]