When you look at light, you know that it refracts, diffracts, and interferes. In fact, it almost seems wavy. However, if you were to look at it a bit closer… Say, at a microscopic level, you would see that the photon – a quantum of energy – carries it. How much energy that photon has to do so can depend on its frequency or wavelength. As you might know, light travels quickly, so you can describe it by its frequency or wavelength.
If you want to know what a photon’s energy is, then you’ve come to the right place. The Planck’s equation determines the number given to each photon, working with its frequency. The formula looks like this:
H = 6.6261 x 10-34 J x s
(Energy) x (time) are the constant units, converting the photons from energies to frequencies.
The equation for Planck looks like this:
E = h * c / λ = h * f
E = photon’s energy
H = Planck constant
C = light’s speed
λ = photon’s wavelength
F = photon’s frequency
Light is a collection of particles, and this formula gives us the single, indivisible quanta of light.
You will quickly discover that when you calculate the energy of a photon, you will get a tiny figure. Planck is small, and the energy of one photon from a green light is only 2.38 eV on a wavelength of 520 nm.
Play around with the photon energy calculator and see what you think. You can also use it to work out the connection between frequencies and wavelengths of photon energy.
