A cheap spectrophotometer can be made using a light-emitting diode (LED) 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?

Question

Quizplus · Accepted Answer

The energy of a photon can be calculated using the formula E = hc/λ, where h is Planck's constant (6.626 x 10^-34 J·s), c is the speed of light (3.00 x 10^8 m/s), and λ is the wavelength (520 nm or 520 x 10^-9 m). Substituting these values gives E ≈ 3.82 x 10^-19 J.

A Cheap Spectrophotometer Can Be Made Using a Light-Emitting Diode