In a piece of iron, you would find the valence electrons moving freely between the cations
Explanation
The valency electrons are those electrons that are present in the outer shell and is ready to involve any chemical reactions . In metals, valence electrons move freely because metals have a relatively low attraction to electrons. They are therefore making metals a conductor of electricity.
Metallic ions have a lattice-like structure that binds them together. It makes the structure of metal ions stable and also, flexible. It helps metal ductile and malleable