Microwave ovens emit microwave energy with a wavelength of 12.8 cm. What is the energy of exactly one photon of this microwave radiation?

We are asked for the energy emitted by a photon using the wavelength given. In this case, we use the planck relation that correlates energy and wavelength using Planck's constant and speed of light as constant of proportionality. The formula is E = hc / w where h is equal to 6.626 x10-34 Js and c is equal to 3 x10 8 m/s. E then is equal to 1.55 x10-24 J