Why Does UV Light Cause Sunburn But Visible Light Does Not?

[clarkandlarry]

Homework Statement

UV light causes sunburn, whereas visible light does not. Explain.

Homework Equations

N/A

The Attempt at a Solution

I'm guessing that it might have sinething to do with the electromagnetic spectrum.

 

[Dick]

Probably. Since it's electromagnetic. Might have something to do with the energy of photons as well. Can you give this a little more thought?

 

[clarkandlarry]

Is it because in UV light, the energy of the photons is much greater than the energy of photons in visible light?
If so, why does the energy of the photons have anything to do with getting sunburn?

 

[Dick]

Because sunburn is caused bythe photons causing damage to organic molecules. What might 'causing damage' have to do with the energy of the photons? Think photoelectric effect.

 

[James3849]

lol... photelectric effect, bits of my skin being imparted with energy and flying off my body?

 

[Dick]

"Photoelectric effect" as in some processes require a minimum photon energy to proceed.

 

[Nick89]

You have probably seen a demonstration of the photoelectric effect once, where your teacher shines a lamp on a cathode/anode device. You might remember that not the intensity, but the frequency (color) of the light was what decided if and how much electrons are released. The same concept applies here.