# Wavelength with just enough energy

1. The problem statement, all variables and given/known data

The work function for chromium is ##7.0 \times 10^{-19} J##.

What is the wavelength of the light that has just enough energy to cause electrons to be emitted from chromium metal?

What is the work function of chromium, in kJ/mol?

2. Relevant equations

3. The attempt at a solution

I believe this question is missing some information? Here’s what I have so far:

##E = K_e + W##
##\frac{hc}{\lambda} = K_e + W##
##\lambda = \frac{hc}{K_e + W}##

I can’t exactly find the kinetic energy here I think.

The second question is easy, just convert the work function to kJ and take it per mol.

http://ift.tt/1hVhysg