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.

oxygen, selenium, tellurium, and polonium.

they're all from the same group as sulfur (group 16).