What are artifacts and why are they important?

Artifacts are things that were made by our ancestors they are important BC without them you will never have stuff like wheels ,cars and stuff like that

Ifound the exercise on the internet. attached is the list mentioned above.in order for a compound to be considered optically active it can't have any axis or plan of symmetry. the molecule  shouldn't also  be superimposable on its mirror image.with such considerations, the compounds that are optically active are: -third compound on the first image is optically active; -second and third compound from the second image are optically actives.

Complementary goods. they go together, thats why one price increase and the others demand increases