International General Certificate of Secondary Education (IGCSE) Chemistry Practice Exam

What property of metals allows them to be shaped into wires?

1. Positivity of ions

2. Delocalisation of electrons

3. Atoms can vibrate freely

4. Movable layers of atoms

The correct answer is: Movable layers of atoms

The property that allows metals to be shaped into wires is the characteristic of movable layers of atoms. Metals have a structure in which atoms are arranged in a lattice formation, and these atoms can slide over one another when force is applied. This movement is possible due to metallic bonding, where the positively charged metal ions are surrounded by a "sea of delocalized electrons." These electrons allow the layers to move without breaking the metallic bond entirely, enabling the metal to be drawn into thin wires, a property known as ductility. The ability of the atoms to move while maintaining the integrity of the metal’s overall structure is essential for forming wires. This feature differentiates metals from other materials that are more rigid and brittle, which would break rather than deform when subjected to similar forces.