If you have more than a specified number of atoms in a microcluster, these atoms will aggregate into a lattice structure with metallic properties. If you have fewer than that critical number of atoms, that microcluster will disaggregate into monatomic atoms with ceramic properties. Monataomic atoms are not held in position by the forces of their neighboring atoms as they are by atoms in a lattice structure. Most elements require a minimum of 14 atoms before they exhibit metallic characteristics. The critical number of atoms for rhodium is 9 and the critical number of atoms for gold is just 2.
Most elements never exhibit metalic characterists.
I am not sure that most metalic elements require a minimum of 14 atoms before they exhibit metallic characteristisc. The significance of this is that if you have two or more gold atoms in a microcluster, it will exhibit metallic characteristics. However, if you have 9 or fewer atoms in a microcluster of rhodium atoms, the microcluster will spontaneously disaggregate to become a group of monatomic rhodium atoms. Apparently, the only force which binds monatomic atoms together is gravity. More insight is needed in this area.