What is the longest-wavelength EM radiation that can eject a photoelectron from silver, given that the binding energy is 4.73 eV? Is this in the visible range?

The longest wavelength is  

It is not in the range of visible light

Explanation:

From the question the question we are told that

   The binding energy is

the kinetic energy of the ejected photoelectron  is mathematically represented as

Where h is the plank constant with a values of  

            f is the frequency of the the EM which is mathematically represented as

Here c is the speed of light with value  

          is the wavelength

So we have  

So making the subject of the formula

Here the maximum kinetic energy is  zero this is because  out of all the electron ejected using a light of a threshold frequency (i.e a photo electron ) the one that has the maximum kinetic energy is none so this implies that maximum  kinetic energy is  zero so the equation becomes

Looking at this we see that it is not in the range of visible light which is  

          400nm - 700nm

it doesn't. it was imagined up in the middle ages.