Solution:Silicon is a semiconductor material. When it is doped with the impurities gallium and arsenic, its ability to capture the sun's energy and convert it into electricity is improved considerably.Hence it is used in Solar Panels.
Silicon is also preferred for IC manufacturing because pure silicon is the least affected by water, acid or steam.
It can withhold a high temperature. For the abundant property of Silicon suitable to industrial production, it is also used in Optical glass.
Ink pen is made of carbon black.