Aphoton has 3.4 × 10–18 joules of energy. planck’s constant is 6.63 × 10–34 j•s.

what is the frequency of the photon?

5.12 × 10–15 hz
1.95 × 1016 hz
5.12 × 1015 hz
1.95 × 10–16 hz

The frequency  of the photon is 5.12  x10 ^15  Hz

  calculation

frequency in photons =  energy / planck's  constant

Energy = 3.4 x10^-18  joules

planck's  constant = 6.63 x0 ^-34 j.s

frequency is therefore=  3.4 x10^-18 j  / 6.63 x10^34 j.s  = 5.12 x10^ 15 Sec

  convert sec into Hz

That is   1 sec  = 1 HZ

therefore 5.12 x10^15 sec  = 5.12 x10 ^15  HZ

metric time was an attempt to create a standard unit of time based off of 10, but it never took off an is not included in the metric system (si)