Explain electrical conductivity of metals. [3 MARKS]
Each point: 1 Mark
1. The property by which metals facilitate the flow of electric current through them is called electrical conductivity.
2. All metals are good conductors of electricity because they contain free or mobile electrons. These free electrons conduct electric current.
3. Silver is the best conductor of electricity. Since silver is expensive, copper and aluminium are commonly used for making electric wires. These metals are next best conductors of electricity. However, iron and mercury offer greater resistance to the flow of current. Therefore, they have low electrical conductivities.