[deepground]

Are free electrons only found in conductive materials? Are they just valence electrons that temporarily leave their orbit or is there an extra abundance of them in everything? Do gases have free electrons?

[enahs]

Lots of molecules have "free valence electrons". Water for instance, has two pairs (4 total); And that fact is one of the reasons why it is so highly polar and gives it some of its amazing properties. Oxygen (O₂) has free valance electrons as well (to answer about gases).

"Free valence electrons" can lead to some interesting properties, such as many of the aromatic properties in aromatic organic compounds.

They also have great influence on the structure.

etc.
etc.

[deepground]

Oh so free electrons are still valence electrons, part of a system, not just floating around looking for a proton...

[enahs]

Oh so free electrons are still valence electrons, part of a system, not just floating around looking for a proton...

Yes/no. I think you are just confusing terms.

There are such things as free electrons separate from a molecule. Look into how a battery works.
That is different then electrons not involved in bonding.

[Yggdrasil]

I think some terminology is the source of some confusion.  I think there are two definitions of "free electrons" floating around in this thread.  The OP used free electrons to refer to conductive electrons, electrons which act to conduct electricity.  Enahs used "free electrons" to refer to lone pairs or electrons not involved in a chemical bond.  These two descriptions of "free electrons" are not the same.

Conductive electrons, such as those found in metals or other conductive materials, are actually involved in chemical bonding.  In a metal, all of the s-orbitals of the metal atoms form a large delocalized set of molecular orbitals which form a "band structure" (see http://en.wikipedia.org/wiki/Band_theory).  Electrons which are excited from the valence band to the conduction band (excitation in metals takes only thermal energy) can easily move about and conduct electricity.

A similar phenomenon occurs with conductive polymers and other conductive materials (e.g. graphite, carbon nanotubes).  Here, the conductive electrons reside in a conjugated pi-bond system which is delocalized across the entire material, allowing the electrons to freely conduct electricity across the material.

In general, electrons residing in lone pairs or orbitals not involved in bonding will not be conductive at all since these orbitals are confined to one atom or one molecule only.

[Matt Lacey]

Something else cool that maybe a lot of people aren't aware of - under certain conditions you can get solvated electrons... pretty much closest thing you can get to 'freely' moving electrons outside of a solid or TEG/FEG.

Dissolve sodium metal in liquid ammonia, and you get...

Na⁰ --> Na⁺ + e^-

The electron's surrounded by ammonia molecules, as ions like sodium and chloride are in salt solution. The solvated electrons give rise to a deep blue colour, it's really rather cool.

-Matt