Photon energy: A light beam from a 2.1-mW He-Ne laser has a wavelength of 633 nm. How many photons does the laser emit in one second? (h = 6.626 × 10^-34 J ∙ s, c = 3.00 × 10⁸ m/s) A) 6.7 × 10¹⁵ B) 8.8 × 10¹⁵ C) 1.1 × 10¹⁶ D) 1.3 × 10¹⁶

Question

Quizplus · Accepted Answer

The energy of a single photon is given by E = hc/λ, where h is Planck's constant, c is the speed of light, and λ is the wavelength. The power of the laser is given by P = N * E, where N is the number of photons emitted per second. Substituting the given values into these equations, we get:E = (6.626 × 10^-34 J s) * (3.00 × 10^8 m/s) / (633 × 10^-9 m) = 3.14 × 10^-19 JP = 2.1 × 10^-3 W = 2.1 × 10^-3 J/sN = P/E = (2.1 × 10^-3 J/s) / (3.14 × 10^-19 J) = 6.7 × 10^15 photons/sTherefore, the laser emits 6.7 × 10^15 photons in one second.

Photon Energy: a Light Beam from a 2