Wavelength = c/Frequency
Since we know that c, the speed of light, is equal to 3 X 10^8 m/s, then
Wavelength = (3 X 10^8)/Frequency
or
Frequency = (3 X 10^8)/Wavelength
Photon energy is not a topic people sit around discussing at the dinner table,
but it is also related as follows:
E (photon energy) = h (Planck's Constant) X Frequency
If you want to relate photon energy to wavelength then use the following:
E(eV) = 1.2406/Wavelength(in micrometers)
There is a relationship between frequency, energy and wavelength.
What we call Light
is only a small part of the Spectrum of
Electromagnetic Radiation.
The fundamental nature of all electromagnetic radiation is the same: it can
be viewed Photon(s) or
Waves and travels at the Speed of Light.
The difference between Radiation in different
parts of the electromagnetic spectrum is a quantity that can be
measured in three basic ways: as the length of a wave, as the Energy of a photon, or as the oscillation of an Electromagnetic Field(s).
Each measurement - Wavelength, energy, or Frequency - has its own characteristic unit. In some parts of the spectrum, frequency
is used most; in others, photon energy or wavelength is. The optical world talks in wavelength, which is measured in metric units (see Metric Unit Prefixes) - meters, micrometers, and nanometers. Do not
bother thinking of in inches,
one micrometer is 1/25,000 of an inch. Frequency is measured in hertz.
Photon energy can be measured in many ways, with one of the most common being Electron Volt (eV) - the energy that an electron gains in moving through a 1-Volt Electric Field.