All metals (copper, iron, lead, magnesium etc) and graphite, a non-metal. Most non-metals (sulphur, iodine, charcoal etc.) Most solid compounds (All gases are non-conductors)
Liquids are classified in three groups as regards their conductivity of electricity:
- Those that pass an electric current and are not decomposed by if (conductors)
- Those that pass an electric current and are decomposed by it (electrolytes)
- Those that do not pass an electric current (non-electrolytes).
In summary, the following substances are electrolytes:
- Molten salts
- Solutions of salts in water
- Solutions of acids
- Solutions of alkalis
Metallic conductivity:
- Electrons flow(carry charge)
- It is a property of elements, graphite and alloys
- It takes place in solids and liquids
- No chemical change takes place.
Electrolytic conductivity:
- Ions flow (carry charge)
- It is a property of ionic compounds
- Takes place in liquids (molten salts) and solutions but not solids
- Chemical decomposition takes place.