Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: Paul Anderson on 24/01/2009 23:36:38

Title: Are there any cases where the atoms do the moving in gas to conduct electricity?
Post by: Paul Anderson on 24/01/2009 23:36:38

Paul Anderson  asked the Naked Scientists:
   
Electrons go down a wire. Electrons pass through old radio valves. Are there any cases where the atoms do the moving in gas?
What do you think?

Title: Are there any cases where the atoms do the moving in gas to conduct electricity?
Post by: Vern on 25/01/2009 00:01:45

Ions which are atoms with missing electrons move in a liquid as in when plating metals and this conducts electricity. Same thing in the liquid of the lead acid battery in your car.

Title: Are there any cases where the atoms do the moving in gas to conduct electricity?
Post by: lyner on 25/01/2009 00:13:06

With an anode of mercury, mercury ions could well migrate to the cathode in an evacuated tube. Vaporising a pool of mercury with a positive potential (an anode) and striking an arc would cause electrons to move one way (much faster)- to the anode and mercury ions to move the other way (much slower) - to the cathode.

Title: Are there any cases where the atoms do the moving in gas to conduct electricity?
Post by: RD on 25/01/2009 07:13:52

High-temperature electrolysis (http://en.wikipedia.org/wiki/High-temperature_electrolysis) ?

Title: Are there any cases where the atoms do the moving in gas to conduct electricity?
Post by: Bored chemist on 25/01/2009 10:49:19

A fluorescent lamp conducts electricity while it's running. Some of that current is caried by electrons but a some is carried by argon ions and mercury ions.
In the inside of a mass spectrometer the current is carried by ions (generally positive) and it's by measuring this current that you can find out how much of a chemical is present in a sample.

Title: Are there any cases where the atoms do the moving in gas to conduct electricity?
Post by: lyner on 25/01/2009 12:45:06

Quote from: sophiecentaur on 25/01/2009 00:13:06

With an anode of mercury, mercury ions could well migrate to the cathode in an evacuated tube. Vaporising a pool of mercury with a positive potential (an anode) and striking an arc would cause electrons to move one way (much faster)- to the anode and mercury ions to move the other way (much slower) - to the cathode.

Durr! I was just describing a mass spec (minus the magnet) without realising it!! I didn't see the wood for the trees.

Title: Are there any cases where the atoms do the moving in gas to conduct electricity?
Post by: lightarrow on 25/01/2009 13:04:27

Quote from: sophiecentaur on 25/01/2009 12:45:06

I didn't see the wood for the trees.

It's a locution? What does it mean?

Title: Are there any cases where the atoms do the moving in gas to conduct electricity?
Post by: Bored chemist on 25/01/2009 13:39:22

Also written as Can't see the forrest for the trees.
Unable to see something obvious.
http://www.phrases.org.uk/bulletin_board/5/messages/1529.html

Title: Are there any cases where the atoms do the moving in gas to conduct electricity?
Post by: Farrah Day on 25/01/2009 14:57:05

If you are talking about atoms as an electric current, the answer to the original question has to be no. Atoms are neutral.  A current carrier needs to be a charged species such as an electron or an ion (+ve or -ve, elemental or molecular).

Title: Are there any cases where the atoms do the moving in gas to conduct electricity?
Post by: lightarrow on 25/01/2009 18:31:47

Quote from: Bored chemist on 25/01/2009 13:39:22

Also written as Can't see the forrest for the trees.
Unable to see something obvious.
http://www.phrases.org.uk/bulletin_board/5/messages/1529.html

Thank you very much, Bored Chemist!

Title: Are there any cases where the atoms do the moving in gas to conduct electricity?
Post by: Vern on 25/01/2009 20:15:47

Quote from: Farrah Day on 25/01/2009 14:57:05

If you are talking about atoms as an electric current, the answer to the original question has to be no. Atoms are neutral.  A current carrier needs to be a charged species such as an electron or an ion (+ve or -ve, elemental or molecular).

Yes; I should have prefaced my answer with: No but;