Yes, a copper penny is a good conductor of electricity. Copper is a metal, and metals are generally good conductors of electricity. This is because metals have a lot of free electrons, which can move easily from one atom to another. When an electric current is passed through a metal, these free electrons move, carrying the current with them.

The conductivity of a metal is measured in siemens per meter (S/m). The conductivity of copper is 59.6 x 10^6 S/m, which is very high. This means that copper is a very good conductor of electricity.

In fact, copper is one of the best conductors of electricity, after silver and gold. This is why copper is used in so many electrical applications, such as wires, cables, and circuit boards.