Question

microwave oven emitt microwave energy with a wavelenght of 12.5cm. what is the energy of exactly one photon of this microwave radiation

Answer 1

Energy equivalent to an Electromagnetic wave
E = hf, where h = Plank's constant= 6.626*10^-34 Js
E = hc/λ
E is the energy of the particle in Joules
f is frequency, λ is wavelength in meters=12.5cm=0.125m, c is the velocity of light = 3*10⁸m/s

E = (6.626*10^-34)(3*10⁸) / (0.125)

E = 1.59 * 10^-24 J

Energy of one photon = 1.59 * 10^-24 J * N_A

                                = 1.59 * 10^-24 J * 6.022 * 10²³ mol^-1

                                = 0.9574 J/mol

Energy of one photon = 9.57 * 10^-4 kJ/mol