1. The problem statement, all variables and given/known data the wavelengths of visible light range from about 380 nm to 750 nm. what is the range of photon energies (in eV) in visible light? a typical fm radio station's broadcast frequency is about 100Mhz. what is the energy of an FM photon of the frequency? 2. Relevant equations eVo=hf-(phi) phi=hfo i don't know how to get fo which is the threshold frequency. thats the only part im stuck with 3. The attempt at a solution i don't know how to get fo which is the threshold frequency.