Electrical Conductivity
Summary: The ability of a substance to allow the flow of electric charge (electrons or ions), measured by how easily current passes through the material. Tags: igcse chemistry keyword Created: 2026-08-06
Electrical conductivity is the measure of a material’s ability to conduct an electric current. For a substance to conduct electricity, it must contain charged particles that are free to move:
- Metals and graphite: conduct because they contain delocalised electrons that are free to move throughout the structure
- Ionic compounds: conduct when molten or aqueous because the ions are free to move; do NOT conduct when solid because ions are locked in fixed lattice positions
- Simple molecular compounds: do NOT conduct in any state because they have no ions or free electrons — molecules are neutral
At IGCSE, the key comparison is between the different structure types and their ability to conduct electricity in different states.
Exam point: Electrical conductivity requires mobile charged particles — delocalised electrons (metals, graphite) or mobile ions (molten/aqueous ionic compounds).
Sources
- Cambridge IGCSE Chemistry 0620 Syllabus (2023-2025), Cambridge Assessment International Education
Common Misconceptions
| Misconception | Reality |
|---|---|
| All solids conduct electricity | Only metals and graphite conduct as solids; ionic compounds and covalent structures are insulators when solid |
| Water conducts electricity | Pure water is a very poor conductor; it’s the dissolved ions in impure water that conduct |
| Graphite conducts because of free ions | Graphite conducts because of delocalised electrons between layers, not ions |