What is the energy of a photon with a wavelength of 12.3?

To find the energy of a photon with a given wavelength (λ in meters), you can use the formula E = hc/λ, where h is Planck's constant (6.626 x 10^-34 J·s) and c is the speed of light (3.00 x 10^8 m/s). Plugging in the values, you can calculate the energy of the photon.