Chemistry definitions, formulas, and structures are presented in question form on 500 separate flash cards, with explanations and chemical reactions indicated on the reverse side. This boxed set of 4 1/2" x 2 3/4" flash cards is designed with a punch hole in one corner of each card. The hole will accommodate a metal key-ring-style card holder enclosed with the cards. Using the holder, students can arrange the flash cards for their Q and A sessions in any sequence that suits their needs--perhaps by general topic, or alternately by leaving out cards with questions and answers that test takers already know well.