Electrical conductivity in different natural materials depends on the presence of free charge carriers, such as electrons or ions, that can move easily through the material when a voltage is applied.
Materials like metals have high electrical conductivity because they have a lot of free electrons that can move easily. In contrast, insulating materials like rubber have low electrical conductivity because they lack free charge carriers.
Semiconductors fall in between metals and insulators in terms of electrical conductivity. They can conduct electricity under certain conditions by either adding impurities to increase conductivity (doping) or by applying an external voltage.
Overall, the electrical conductivity of natural materials is determined by their atomic and molecular structures, as well as the availability of free charge carriers within the material.
