## anonymous one year ago What is the energy of a photon of light having a wavelength of 4.5 x 10-7 meters? (Planck’s constant is 6.626 x 10-34 joule seconds; the speed of light is 2.998 x 108 m/s) 2.9817 x 10-40 joules 4.4143 x 10-19 joules 6.6745 x 10-26 joules second 9.9456 x 10-49 joules 19.864 x 10-26 joules/second

Energy ($$E$$) is related to frequency ($$\nu$$) of light by Planck's constant ($$h$$), $$E=h \nu$$ The speed of any wave ($$c$$) is just the distance it travels (a wavelength, $$\lambda$$) divided by the time it takes, which is the inverse of the period which is just the frequency ($$\nu$$), $$c = \lambda \nu$$