Titanium (phi=6.94x10^-19 J) and silicon (phi=7.77x10^-19 J) surfaces are irradiated with UV radiation with a wavelength of 245 nm

Question

A chemistry problem pertaing to finding the wavelngth

Answer 1

What is your question?  I assume you want to find the kinetic energy of the ejected electron in each case.  First, find the energy of the incident photon, then subtract from that the work function Φ, and that is the kinetic energy E of the ejected electron.

 

E = hc/λ - Φ

 

h = 6.63 x 10^-34 Js

c = 3.00 x 10⁸ m/s

λ = 245 x 10^-9 m

 

Titanium:

 

E = (6.63 x 10^-34 Js)(3.00 x 10⁸ m/s) / (245 x 10^-9 m) - (6.94 x 10^-19 J)

E = 1.18 x 10^-19 J

 

Silicon:

 

E = (6.63 x 10^-34 Js)(3.00 x 10⁸ m/s) / (245 x 10^-9 m) - (7.77 x 10^-19 J)

E = 3.48 x 10^-20 J