# How many delocalised electrons in gold?

How can we determine how many delocalised electrons every atom of gold contributes to the 'sea of delocalised electrons'? More generally, how can we determine the number of electrons any metal contributes? Must we have thermodynamic data to determine this?

• According to the book Solid State Physics (Ashcroft, Mermin), the Drude model (electron sea model) as originally proposed gives no theoretical basis for finding how many electrons per atom in a metal are delocalized. – Nicolau Saker Neto May 29 '15 at 22:27

Above the s band you'll have a similar p band. In gold, the p band is unoccupied, while the s band is half full (gold has 6s$^1$). However, IF the bottom of the p band overlaps with the top of the s band, the s electrons can easily move into the bonding MO's at the bottom of the p band. They can also move into any vacant orbitals in the s band that are just above the highest occupied orbital. In either case, the s electron will be delocalized.