When you exposed the precipitate, silver chloride to light, was this result a physical or chemical change?

It is a chemical change since the silver is chemically turning into silver sulfide. Chemical changes must involve a reaction. A hint that this is a chemical reaction is that there is a color change involved (from silver to black), and the tarnish can be removed without removing the unreacted silver.

atomic number of carbon is 6

electronic configuration of carbon is 1s²2s²2p²

orbital diagram of c is as shown here in the image.