Which category conducts electricity in solid form?

• A. Metals
• B. Non-metals
• C. Metalloids
• D. Noble gases

Answer: (A)

Electrical conductivity in a solid relies on charges that can move freely. In metals, atoms form a lattice where many electrons are not bound to any one atom. These delocalized electrons act as a sea that flows when a voltage is applied, so electric current passes through the solid easily. That free-electron model is what makes metals good conductors in the solid state.

Non-metals usually lack these free electrons in solid form, so they’re poor conductors. Metalloids sit in between and can conduct to some extent, depending on conditions. Noble gases, when solid, don’t have mobile charges to carry current, so they don’t conduct electricity.