Calculate the threshold frequency for a metal with a work function of 3eV

The equation for work function is: W = hf

So, this is rearranged to: f = W/h where h is planck's constant.

Therefore, if we know the work function then we can work out the threshold frequency.

Don't forget to convert 3eV into J. 1eV = 1.6 x 10^{-19} J.

f = (3 x 1.6 x 10^{-19})/(6.63 x 10^{-34})
f = 7.24 x 10^{14} Hz