To be able to see what resources have or have not been accessed in your course room (and by who) you must use the statistics tool called New Analytics. Go to the Home of your course room and then click New Analytics in the right side column.

Screenshot with arrow pointing to New Analytics on course home page.

In New Analytics, switch to the tab Weekly Online Activity. Click the week you would like to check up on in any of the page view or participation graphs below.

Weekly Online Activity in New Analytics.

On the details page for a week, switch to the Resources tab to see number of students, page views and participations for each object.

Students: Number of unique students with at least one page view.
Page views: Number of visits for the resource.
Participations: Number of submissions in assignments, replies to discussions, quiz attempts or page contributions.

Week details of accessed resources.

To see who the students are that did or didn't view/participate, click the digit beside each label.

By switching between the tabs at the top you can find out who viewed, didn't view, participated or didn't participate for each resource (during the selected week). By expanding the recipient list you can see the names of the students. If you would like to message the students you can do so just below without having to visit the Inbox.

Drill down into who did or didn't view any resource.