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Topic: Why is everything oxidized?  (Read 5516 times)

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Offline poobear

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Why is everything oxidized?
« on: October 22, 2008, 04:07:41 PM »
I heard today that a fluorosence material cant be used for a long time.
I asked about this, and I got the answer that its sensitive to light (I guess its for the activation energy).
I asked what happens, and got the answer that its oxidized by the light.
I also got the answer that this is not just for fluorophores, the rule is basicly for everything.
So my little question is, why is everything being hit by oxidation (if you wait long enough)?

If I can recall the little I have read about biochemistry, oxidation is used in the metabolic pathways to get energy from reduced stuff we eat.
Is that the answer, that compounds is being oxidized because the product is in a lower energy state?

(Makes me think what it would be if we had our genetic material as the oxidated carbohydrates, maybe less damage from UV light)

/ Hopes someone understands what I asked
Thanks

Offline Arkcon

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Re: Why is everything oxidized?
« Reply #1 on: October 22, 2008, 07:49:15 PM »
Quote
So my little question is, why is everything being hit by oxidation (if you wait long enough)?

Oh, everything is, especially when it absorbs light, or other radiation to excite (raise the energy level of) some of it's conjugated double bonds.  Everything oxidizes, when surrounded by an oxidizer, which on the surface of the planet Earth, is everywhere.

Well, almost everywhere.  Wine, sealed in a pitch coated amphora, and submerged in a sunken ship in the Aegean Sea, remains wine, even for thousands of years.  It becomes vinegar much sooner, in a corked bottle on the surface.  Likewise, petroleum deposits endure for a long time, underground, but are burned rapidly in engines, or can even be attacked by microbes.
Hey, I'm not judging.  I just like to shoot straight.  I'm a man of science.

Offline DrCMS

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Re: Why is everything oxidized?
« Reply #2 on: October 23, 2008, 04:55:48 AM »
I heard today that a fluorosence material cant be used for a long time.
I asked about this, and I got the answer that its sensitive to light (I guess its for the activation energy).
I asked what happens, and got the answer that its oxidized by the light.

Not necessarily.  The fluorescent materials used in washing poweders and added to paper are based on stilbene.  In the trans form they are fluorescent but when they absorb light they are converted to the cis form which is not.

Offline poobear

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Re: Why is everything oxidized?
« Reply #3 on: October 23, 2008, 07:50:59 AM »
Oh, everything is, especially when it absorbs light, or other radiation to excite (raise the energy level of) some of it's conjugated double bonds.  Everything oxidizes, when surrounded by an oxidizer, which on the surface of the planet Earth, is everywhere.

Electrons are excited by the light -> electrons gets a longer distance to the nucleus -> they get less affinity to the nucleus -> something with higher affinity to the electron (e.g. oxygen) steals the electron.
Did I understand you right?

You talk about conjugated double bounds. Why are these so sensitive to this?
Doesnt they have the same energy levels etc like normal pi-bonds? Something to do with that they "float around" in the molecule?

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