Conductors – These allow electricity to pass through (usually metals)
Semi – conductors-These conduct only under some conditions e.g. only when hot e.g. silicon, graphite
Non – conductors (insulators) – Do not conduct electricity at all e.g. plastic, wood
Conductors are separated into
- Metals and Graphite
Metal and Graphite – These conduct due to the presence of free mobile electrons. The material remains the same.
Electrolytes – conduction happens due to free ions. There is a chemical breakdown of the electrolyte. They do not conduct in the solid state.
Electrolytes may be
- Strong electrolytes – These are completely ionized in aqueous solution e.g. strong acids(H2SO4, HCl)
- Weak electrolyte – These are partially ionized in aqueous solution e.g. weak acids and base – ethanoic acid, aqueous ammonia)
- No electrons are lost or gained
- Electrons leave one end and enters the other end