Question

Electromagnetic radiation with a wavelength of 575 nm appears as yellow light to the human eye. The energy of one photon of this light is 3.46 × 10 -19 J. Thus, a laser that emits of energy in a pulse of light at this wavelength produces ________ photons in each pulse.

Answer 1

Answer:

9.12 * 10^20 photons

Explanation:

Given that;

E=n⋅h⋅ν

Where;

E= energy of the electromagnetic radiation

n = number of photons

h = Plank's constant

ν = frequency of electromagnetic radiation

Hence;

n = E/hν

n = 3.46 × 10 -19/6.6 * 10^-34 * 575 * 10^-9

n = 3.46 × 10 -19/3795 * 10^-43

n=  9.12 * 10^20 photons