Photon Question-Energy Quantization Question---please help! This is a somewhat simple question I'm just unsure what relations to use. I found an equation relating number of protons to power and frequency but i'm not sure how to apply it to this case. EQUATION? Power = energy per unit time = (energy per photon) * (photon per unit time) = (h*f) * (photons per unit time) *where* Power = wattage h = Planck's constant f = frequency. QUESTION A certain laser outputs pure red light (photon energy 1.8 eV) with power 550 milliwatts (0.55 watts). How many photons per second does this laser emit? photons/s -Thanks!!