Why is silicon (Si), the principal element used in constructing solar cells? Question 6Select one: A. Pure Si is a good conductor of electricity because the electrons are all locked in the crystalline structure B. When light, in the form of photons strikes the Si cell, its energy frees electron-hole pairs C. An atom of Si cell has 12 electrons, arranged in two different shells D. The band gap energy in a Si cell is extremely high E. Has low thermal conductivity