In gases and electrolyte solutions, ions are carriers of electric charge. Thus, during the passage of an electric current in these media, a transfer of matter occurs. On the contrary, in metals, the carriers of electric charge are electrons, and in semiconductors, electrons and holes, so that in these media, the transfer of matter does not occur.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.