A light-emitting diode has a power output of 0.3 W. If 590 nm is the average wavelength of the source, about how many photons are emitted per second? (h = 6.63 *10^-³⁴ J.s, c = 3.00 *10⁸ m/s, and 1 nm = 10^-⁹ m) A) 10²¹ B) 10²⁵ C) 10¹⁸ D) 10²⁹

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Quizplus · Accepted Answer

The energy of one photon is calculated using E = hc/λ. Substituting the given values, E = (6.63 x 10^-34 J·s)(3.00 x 10^8 m/s) / (590 x 10^-9 m) = 3.37 x 10^-19 J. The number of photons emitted per second is the power output divided by the energy per photon: 0.3 W / 3.37 x 10^-19 J = approximately 10^18 photons per second.

A Light-Emitting Diode Has a Power Output of 0