Why is it that only ozone, oxygen and nitrogen absorb UV rays?

Question

This is actually a 3-part question.
1. Why is it that only ozone, oxygen and nitrogen absorb UV rays?
2. How do they do it?
3. If oxygen breaks apart then recombines to form ozone, now that some of the UV rays are getting through the ozone layer, why aren't they forming ozone in the lower atmosphere?
Thanks.
And anything else that can help me understand this please!
Please explain in terms of chemistry, not just a basic overview.

Answer 1

OK, here goes.

UV-C is absorbed by nitrogen and oxygen (and CO2 and...). Their molecular bonds are shattered when they do this. As they recombine, some ozone gets formed. There is no UV-C left by the bottom of the "ozone layer".



UV-B and more energetic radiation can be absorbed by ozone. UV-B breaks ozone down, but oxygen and nitrogen are transparent to UV-B.



UV-A, the "tanning rays" is not energetic enough to break down stronger bonds, but can drive other chemical processes. Like formation of vitamin D in humans.



Loss of ozone lets more UV-B through, and UV-B will not shatter oxygen, and will not form ozone. UV-B is the stuff that we and our animal and plant friends are transparent to... except for our DNA. UV-B directly attacks our DNA.

Answer 2

Organic molecules absorb UV too. In fact, a whole deal of various inorganic molecules do absorb UV light as well. However, the UV light that comes from the sun interacts first with O3, O2, and N2 because these gases are in our atmosphere and the remainder rays make it down to the surface of the Earth. Nevertheless, it's true they do absorb UV-radiation and the reason why is because 1) the energy in a photon of UV light matches up with the energy difference between the highest occupied molecular orbital and the lowest unoccupied molecular orbital of each molecule. 2) In other words, the transition from the orbital containing the outer most electrons to the next orbital is equal to a photon of UV light.

3) There's an equilibrium between all the reactions:

O2 + hv --> 2 O

O2 + O --> O3

O3 + hv ---> O2 + O

It is a constant, on-going reaction; therefore, very little UV light ever reaches us down here.

Answer 3

maximum UV Ray and maximum fee of epidermis maximum cancers. Queensland Australia. tremendous hollow contained in the Ozone over oz.. tremendous hollow contained in the Ozone over the North Pole. Ozone Blocks UV, so certain there's a relationship between UV and epidermis maximum cancers.

Answer 4

1. they are the elements with the chemical layout that allows them to bond with the uv 'isotopes', or radioactive ions, but they aren't the only, just the most abundant, least reactive and organic.

2. it would require a chemical reaction, but the only one with the catalyst that i know off hand is oxygen ( the extra o )

3. ozone is lighter than oxygen and nitrogen, so it floats up.