Energy Carried by Electromagnetic Waves Video Lessons

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# Problem: Rod cells in the retina of the eye detect light using a photopigment called rhodopsin. 1.8 eV is the lowest photon energy that can trigger a response in rhodopsin.1. What is the maximum wavelength of electromagnetic radiation that can cause a transition? (in nm)2. In what part of the spectrum is this? (visible light, infrared, x-ray, or ultraviolet)

###### FREE Expert Solution

In this problem, we'll use the expression of the energy of an electromagnetic wave.

The energy of an electromagnetic wave:

E = hf = hc/λ where h is Plank's constant, f is the frequency, c is the speed of light, and λ is the wavelength.

Relationship between eV and J:

1eV = 1.6 × 10-19 J

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###### Problem Details

Rod cells in the retina of the eye detect light using a photopigment called rhodopsin. 1.8 eV is the lowest photon energy that can trigger a response in rhodopsin.

1. What is the maximum wavelength of electromagnetic radiation that can cause a transition? (in nm)

2. In what part of the spectrum is this? (visible light, infrared, x-ray, or ultraviolet)