Currently there are two main ideas of those electrons that move in a conductor:
those electrons moving are loosely bound to the valence shells of the atoms in the lattice
those electrons moving are delocalised
Now for 1. these questions are saying they are loosely bound:
where annav says:
The photons will at first meet the surface of the metal, where the first thing they interact with is the conduction band electrons that are very loosely bound, and thus have small average kinetic energy to contribute to the interaction.
where Sinkfly says:
In fact, in my introductory solid-state physics book, the additional electron contributed by a donor in a doped semiconductor is referred to as "loosely bound" to the donor ion, requiring a push into the conduction band to break free and become a charge carrier.
Now for 2. these questions say they are not loosely bound but they are delocalised:
where my2cts comments say:
Electrons are never bound to shells. - "The electrons can move thus from one atom to the other atom's valence shell. " No they don't. They are delocalised. -
- Which one is right? Are electrons (that move) in a conductor loosely bound to the valence shells of the atoms or are they delocalised? I am asking for a QM level explanation.