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Electrical conductivity of solid materials

Solid materials can be classified into two main categories:
- Electrical conductors that can be crossed by an electric current.
- Insulators that don't conduct electric current.

To determine whether a material is conductive, a test of conductivity can be performed using the following circuit:

Test of conductivity on solid materials

The principle of this test is simple:
- If the bulb lights, it indicates that the electric current flows then the material is conductive.
- If the bulb doesn't light, it indicates the electric current doesn't flow so the material is insulative.

Test results:

Tested materias Test results:
Iron Conductor
Zinc Conductor
Aluminium Conductor
Copper Conductor
Copper sulfate powder Insulator
Salt powder Insulator
Wood Insulator
Plastic Insulator

This test permits to show that only metals are conductors and most other solid materials are insulators.
This characteristic can be explained by their microscopic properties

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