The repeat unit in a metal is an atom or group of atoms. For example, the repeat unit in a pure crystalline metal with a simple cubic structure is one metal atom.

In summary, a pure crystalline solid is composed of a regular array of a repeated unit. The repeated unit can be a single atom, a molecule, or a neutral group of positive and negative ions.

Click the links on the right to highlight one repeat unit in a pure crystalline metal with a simple cubic structure or to return to the initial structure.