In a study examining whether restrictions on cell phone use result in differences in performance on a memory test than no restrictions, determining that no differences between groups exist in terms of typical cell phone use and GPA prior to the start of the study:

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.