"but only metals are able to conduct electricity"
This is incorrect.
Any substance that contains free electricity carriers will conduct electricity.
Examples of electrical conductors that are not metals:
1. Liquid electrolytes
2. Solid electrolytes
3. Semiconductors
4. Ionized gases
5. Vacuum in which electrons or ions have been injected by some means
All of the above are used in common devices.
The metals are solid or liquid electrical conductors which contain free electrons that are intrinsic, i.e. not produced by various methods, like in semiconductors.
Besides free electrons, metal have a second characteristic, which was used already in the 18th century to distinguish metals from semi-metals.
While this distinction is seldom mentioned nowadays, it remains useful. Metals have both free electrons and a crystal structure that allows plastic deformation (i.e. with high coordination number), while semi-metals have free electrons, but they have a crystal structure that does not allow plastic deformation, i.e. they are fragile. Examples of semi-metals: graphite, antimony, bismuth.
Any substance that contains free electricity carriers will conduct electricity. Examples of electrical conductors that are not metals: 1. Liquid electrolytes 2. Solid electrolytes 3. Semiconductors 4. Ionized gases 5. Vacuum in which electrons or ions have been injected by some means All of the above are used in common devices.
The metals are solid or liquid electrical conductors which contain free electrons that are intrinsic, i.e. not produced by various methods, like in semiconductors.
Besides free electrons, metal have a second characteristic, which was used already in the 18th century to distinguish metals from semi-metals.
While this distinction is seldom mentioned nowadays, it remains useful. Metals have both free electrons and a crystal structure that allows plastic deformation (i.e. with high coordination number), while semi-metals have free electrons, but they have a crystal structure that does not allow plastic deformation, i.e. they are fragile. Examples of semi-metals: graphite, antimony, bismuth.