## Question on excited atoms emitting light and Neon signs

$c=\lambda v$

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Joshua Yang 1H
Posts: 22
Joined: Mon Jan 08, 2018 8:19 am

### Question on excited atoms emitting light and Neon signs

So we've encountered several problems in our chem HW where an excited atom will emit a certain light, and we would determine the energy of the photons emitted by the excited atom.

Looking at this from an application point of view, do neon light signs do the same kind of thing to emit light?

I'm assuming the neon gas inside the tubes are "excited" by somehow sending electricity through the tubes and the excited neon atoms then emit light, lighting up the sign. This is just what I'm assuming is happening. If anybody knows anything more about this topic, I'd love to hear :)

Alesha Vaughn 1E
Posts: 18
Joined: Fri Apr 06, 2018 11:05 am

### Re: Question on excited atoms emitting light and Neon signs

This is really a interesting topic actually so I decided to research and this is what I found. Gases at atmospheric pressure are not good conductors of electricity. So, to pass a current through a gas requires a gas-discharge tube, which is a glass tube with two electrodes sealed through its walls.. When a voltage is applied to the two electrodes and the pressure of the gas in the tube is lowered at which a current flows, the gas begins to glow. The glow will usually appear when the pressure is between 5 and 15 torr. Neon signs are made in tubes with having an electrode at each end and is filled with a gas at low pressure and a high voltage is applied to the electrodes. Apparently depending on which gas in the tube determines the color of the glow. Neon produces red, Helium produces white to orange, Argon produces purple, etc...

Joshua Yang 1H
Posts: 22
Joined: Mon Jan 08, 2018 8:19 am

### Re: Question on excited atoms emitting light and Neon signs

Alesha Vaughn 1E wrote:This is really a interesting topic actually so I decided to research and this is what I found. Gases at atmospheric pressure are not good conductors of electricity. So, to pass a current through a gas requires a gas-discharge tube, which is a glass tube with two electrodes sealed through its walls.. When a voltage is applied to the two electrodes and the pressure of the gas in the tube is lowered at which a current flows, the gas begins to glow. The glow will usually appear when the pressure is between 5 and 15 torr. Neon signs are made in tubes with having an electrode at each end and is filled with a gas at low pressure and a high voltage is applied to the electrodes. Apparently depending on which gas in the tube determines the color of the glow. Neon produces red, Helium produces white to orange, Argon produces purple, etc...

Niiiiiiice :) that is actually pretty dope

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