In: Chemistry
When light of wavelength equal to 364 nm strikes a metal, the kinetic energy of the ejected electron is 4.12 × 10-19 J. What is the work function of the metal?
Hi,
The given values are Wave length = 364nm
KE of ejected electron is = 4.1210-19 J
Now form the Photo electric effect its given that
h = + KE ( = work function, = frequency, = c/, h= plank's constant =6.626 10-34 Js-1 )
= (3.0108 cm/s)/ 364 10-9 cm
= 8.2417 1014 s-1
Now, substitute in the above equation,
6.626 10-34 Js-1 8.2417 1014 s-1= + 4.12 10-19 J (given)
54.609 10-20 J = + 4.12 10-19 J
= 54.609 10-20 J - 41.2 10-20 J
= 13.409 10-20 J
Therefore the workfunction of metal is 13.409 10-20 J.