Which of the following shows similar conductivity properties as copper?
Answer & explanation
Correct answer: option 1
The answer is 1. \(ReO_2\).
\(ReO_2\) is a transition metal oxide with a conductivity similar to copper. It has a conductivity of about 1000 S/m, which is about 60% of the conductivity of copper.
\(CdSe\) is a semiconductor with a conductivity of about 100 S/m. \(TiO\) is an insulator with a conductivity of about 10-10 S/m. GaAs is a semiconductor with a conductivity of about 10000 S/m.
\(ReO_2\) is a good conductor of electricity because it has a high number of free electrons. The electrons are delocalized, meaning they are not bound to any particular atom. This allows the electrons to move freely through the material, which is what allows it to conduct electricity.
\(CdSe\) and \(TiO\) are both semiconductors. In semiconductors, the valence band is partially filled with electrons. This means that there are not enough electrons to fill the conduction band, so the material does not conduct electricity as well as a metal.
\(GaAs\) is also a semiconductor, but it has a higher band gap than \(CdSe\) and \(TiO\). This means that it has more energy required to excite an electron from the valence band to the conduction band, so it is a better conductor of electricity.