The energy of a photon is equal to the product of planck's constant,h and speed of light,c over the wavelength,y. Hence, e=h\(\frac{c}{y}\). h is equal to 6.626110^-34 Js, c is equal to 310^8 m/s and y= 12.7 cm or 0.127 m. Substituting, energy is equal to 1.565210^-24 Joules.
