http://freerice.com/#/chemical-symbols-basic/1005
Trivia questions in a variety of subjects, including chemical symbols
http://portal.acs.org/portal/PublicWebSite/volunteer/chemambassadors/futurechemists/CNBP_023888
ACS has come up with a guide to becoming a resource in the classroom, including planning classroom visits, how to discuss topics with children, and sample activities and demonstrations to do with students.