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what is shinier? gold or silver

97guns

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#1
and does pt/pd even shine?

there are scenes of gold shining bright in several movies but can't think of any where its silver
ive heard silver is the most reflective element, does that mean its the shiniest?
 

Irons

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Gold. You cannot polish a turd. :smokin:
 
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#3
Austin-Powers-Silver-Fembots.jpg
.....................
 

Irons

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Challenge accepted and upped..................


goldgirl7.jpg
 

Argentium

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AgBar

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That graph of reflectivity vs wavelength was surprising to me, as I had thought silver had the highest reflectivity in the visible light wavelengths and gold had higher reflectivity in IR. This counts as my "learn something new everyday" moment! Thanks!!

Depends on definitions, I suppose.

As you said: In the near infrared (roughly 0.7 to 2 um wavelength) Gold is the shiniest, and Silver is generally more reflective than Gold in the visible (~0.4 to ~0.7 um). Aluminum is more reflective than Silver in the Blue region, Silver more reflective towards the Reds.

But over a broad range from mid-IR up through UV, Aluminum is pretty much the "whitest" metal (reflects efficiently and more-or-less evenly for all wavelengths).

There are optical coatings that are extremely efficient reflectors at certain wavelengths. These are usually called "laser mirrors" or some such, as they are designed for one specific wavelength: that of the laser source.
 
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Irons

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w1.jpg
 
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May we PUHLEEEZE be serious??


It weren't SILVERfinger!! :cheerful:
 
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Irons

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............................
w1.jpg
 
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#15
cate-blanchett-elizabeth-armor1.jpg

morgana.jpg

Lara-in-Armor.jpg
................
 
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Argentium

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Depends on definitions, I suppose.

As you said: In the near infrared (roughly 0.7 to 2 um wavelength) Gold is the shiniest, and Silver is an eensy-teensy bit more reflective in the visible (~0.4 to ~0.7 um). But over a broad range from mid-IR up through UV, Aluminum is pretty much the "whitest" metal (reflects efficiently and more-or-less evenly for all wavelengths).

But there are optical coatings that are extremely efficient reflectors at certain wavelengths. These are usually called "laser mirrors" or some such, as they are designed for one specific wavelength: that of the laser source.
It's been a long time since Uni, but I seem to remember that reflectivity is related to how the d-orbitals are filled? Aluminum doesn't have any electrons in d orbitals, so how does that work?
 

Ragnarok

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#21
Silver is the preferred metal for telescope reflector mirrors in the visible spectrum, but must be overcoated to prevent tarnishing, this and the cost is why aluminum has mostly replaced it for this purpose.
OTOH, gold is the preferred metal for reflective optics in the red/infrared portions of the spectrum.

2c, R.
 
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#22
No more pictures of redheads dressed in silver, please. I'm about to pass out!

:bloomingrose1kz::date::36_3_13::s11::36_3_12::love30:
Whatever you say Br'er AgBar...

Silver_Bells_1.jpg
 
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#24
Right you are...

maureenohara.jpg

O' course some of her best are in B&W, though...

Maureen-O'Hara-Hunchback-1939.jpg

Maureen-O-Hara..jpg
 

gliddenralston

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#25
I thought porn was barred from gim.
 

AgBar

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#26
It's been a long time since Uni, but I seem to remember that reflectivity is related to how the d-orbitals are filled? Aluminum doesn't have any electrons in d orbitals, so how does that work?
It's more about the outer-most (least-bound) electrons than about the specific orbitals that they're in. As you point out, the light metals, Al, Li, Mg, and such, only have s- and p-orbitals occupied in the ground state. But it is the interaction of the outer electrons -- 2s1 for Lithium, 3p1 for Aluminum, etc. -- with incoming light that causes reflectivity in a metal. It's a bulk effect of the conduction-band electrons in a metal; individual atoms act a bit differently.

The "color" at higher energies (Hard-UV, X-ray, gammas) can be due to electrons closer to the nucleus, or even interactions in the nucleus itself: x-ray fluorescence, for example. But for anything near visible light energies, the outer electrons strongly dominate the effect.
 

Argentium

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It's more about the outer-most (least-bound) electrons than about the specific orbitals that they're in. As you point out, the light metals, Al, Li, Mg, and such, only have s- and p-orbitals occupied in the ground state. But it is the interaction of the outer electrons -- 2s1 for Lithium, 3p1 for Aluminum, etc. -- with incoming light that causes reflectivity in a metal. It's a bulk effect of the conduction-band electrons in a metal; individual atoms act a bit differently.

The "color" at higher energies (Hard-UV, X-ray, gammas) can be due to electrons closer to the nucleus, or even interactions in the nucleus itself: x-ray fluorescence, for example. But for anything near visible light energies, the outer electrons strongly dominate the effect.
Makes sense. I'm trying to remember, perhaps I'm thinking that the d-orbitals have something to do with the color of copper and gold? Age is a terrible thing, sometimes. :(
 

AgBar

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#29

Argentium

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#30
...was this what you were thinking of?

http://en.wikipedia.org/wiki/Relativistic_quantum_chemistry#Color_of_gold_and_caesium

(couldn't quickly find a decent article that wasn't behind a paywall, so a few paragraphs from Wiki it is)
By Jove, you got it! Thanks! That bit about the color of cesium, I've heard about that before. I have a 5 g sample of it in my element collection and it looks silvery to me, but the Wiki reference said one must have a "significant" quantity of it, which evidently is more than 5 grams!
 

voodoo1951

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#31
Ladies and gentlemen, it's a very simple answer, Break out the old slide rule and get back to me with your answer when you figure it out, OK?
 

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Argent Dragon

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#32
The boring scientific answer : When it comes to reflective properties, there's a reason that silvering is used to produce mirrors.

 

AguA

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#33
The boring scientific answer : When it comes to reflective properties, there's a reason that silvering is used to produce mirrors.

It may be the silvering that reflects better but it's the gold framing that makes an ugly mug look prettier...lol.
 

AgBar

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#34
The boring scientific answer : When it comes to reflective properties, there's a reason that silvering is used to produce mirrors.

I mis-spoke in my reply above (#8, since edited) when I said that silver is only slightly more reflective than gold in the visible band. I was reading my own graph in frequency, when it was actually plotted in wavelength. My bad. And the quote of my original post shows the :censored:-up for all to see. :biggrin:


To clarify: towards the red end of visible light, Silver is indeed the most reflective. Aluminum is more reflective toward blue.

Near-Infrared to Mid-IR, Gold is the winner.

Broad-band IR thru UV, Aluminum wins overall.
 

Ragnarok

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#35
"How shiny" depends somewhat on the color(s)/wavelength of light under consideration. Here's a chart of metal reflectance (from Wiki). For those not familiar with the wavelengths as related to color, 400nm (violet) is the "short wavelength end" of the generally accepted visible spectrum, while 700nm (deep red) is the other, "long wavelength end" (some people can see a bit past these limits). Here are the representative wavelength ranges for the visible spectrum ("nm" = nanometers) to help interpret the charts:

Violet: 400 - 420 nm
Indigo: 420 - 440 nm
Blue: 440 - 490 nm
Cyan: 490 - 505 nm
Green: 505 - 570 nm
Yellow: 570 - 595 nm
Orange: 595 - 620 nm
Red: 620 - 780 nm

Metal-reflectance.png

Interesting to note that silver at one point in the UV, around 315-320nm, is essentially "black" (!).
Also of interest is how much gold absorbs in the mid-to-short wavelengths, which is the reason for its apparent reflected color; OTOH if you look through a piece of gold leaf toward a bright white light, you can see the complementary blue-green part of the spectrum that passes into and through the leaf on account of its thinness.

Just FYI, the "shiniest" materials are man-made optical coatings consisting of alternating layers of high-and low-refractive index materials deposited on a suitable substrate; these can be used to produce mirrors which reflect greater than 99.99% of the light which falls on them.

More info at http://en.wikipedia.org/wiki/Optical_coating
...

And now for something completely different, the worlds shiniest living thing, is a berry: http://blogs.discovermagazine.com/n...ny-fruit-pointillist-pixellated/#.UXRpqUqwX50

R.
 
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