BioMedical Admissions Test (BMAT) 2025 – 400 Free Practice Questions to Pass the Exam

The correct answer is indeed the type of structure that does not conduct electricity even when molten: giant covalent structures. In a giant covalent structure, atoms are bonded together by strong covalent bonds in a lattice formation. This network of strong bonds does not allow for the movement of charged particles like ions or free electrons, which are essential for electrical conductivity.

Even when melted, these structures remain intact as a continuous network of atoms, and the electrons involved in covalent bonding are not free to move. Therefore, there are no charged carriers available to conduct electricity. In contrast, the other types of structures have different properties:

Giant ionic structures contain ions that are free to move when molten, allowing them to conduct electricity. Simple molecular structures consist of discrete molecules held together by intermolecular forces, and while these forces can weaken upon melting, the molecules themselves do not possess free-moving charged particles to conduct electricity. Giant metallic structures have free electrons within their lattice that facilitate the conduction of electricity, even in the molten state.