Photon Energy Og Green Lightwaves?
December 12, 2009 by
Filed under Yahoo! Answers
A cheap spectrophotometer can be made using a light-emitting diode as the source of the light. Assume that you build one of these spectrometers using an LED that gives off green light with a wavelength of 520 nm. What is the energy of a photon of this green light?
j_christ on Sat, 12th Dec 2009 2:04 am
First, convert the wavelength to frequency via the equation: c= (wavelength) * (frequency), where c is the speed of light (3.0e8 m/s). Then, slip the frequency into the next equation: E= h* (frequency)….E will be the energy in joules, and h is Plank’s constant….can’t remeber the value off the top of my head, but the units are joule-seconds….
teroy on Sat, 12th Dec 2009 7:34 am
E = h*frequency
c=wavelength*frequency =>frequency = c/wavelength
E = hc/wavelength
= (6.626 x 10^-34 Js*3 x10^8 m/s)/520nm(1m/1 x10^9 nm)
= 3.82 x10^-19 Joule
best answer?