Which element is likely to be the best conductor of electricity? copper lithium iodine silicon

Copper is the best conductor of electricity.

Explanation:

Copper atom has free electrons which are free to move and thus copper easily loses electrons to acquire a positive charge. Copper has 1 or 2 positive charge.

The specific conductivity of copper is very high and this also makes it a good conductor of electricity.  

Whereas, lithium has only 1 valence electron so it forms and hence can conduct electricity.

As compared to copper it is less conducting because copper can attain higher positive charge.

Iodine does not have any free electrons. So, it does not conduct electricity.

Silicon has a giant lattice structure where free electrons are being locked up. Hence, due to this electrons are not available for conductivity and this makes it a poor conductor of electricity.

Thus, it can be concluded that copper is the best conductor of electricity.