Materials made of which two metals are classified as semi-conductors?

The two metals that are classified as semi-conductors are actually not among the choices listed. Instead, semi-conductors are typically materials like silicon and germanium that have electrical conductivity between that of conductors and insulators.

However, if you consider the choices provided, copper and silver are known for their excellent conductivity rather than being semi-conductors. Metals like gold and silver are considered good conductors due to their ability to carry electrical current efficiently.

To clarify, while copper and silver are often mentioned in discussions surrounding electrical materials because of their conductive properties, they do not exhibit the characteristics that define semi-conductors, such as the ability to control electric current under varying conditions or to create p-n junctions for electronic applications.

In practice, for actual semi-conductor applications, materials typically include elements from group IV of the periodic table, such as silicon, which has a unique ability to conduct electricity under certain conditions, making it essential in modern electronics.