Students assigned a portion of the periodic table.  Generally, a student is given a column of the main group, but this can easily be varied, depending on the size of the class.

 Students then submit Jeopardy-style questions (a statement, to which the "answer" can be stated in the form of a question) about each element in their portion of the table.  The instructor then breaks the questions into categories (Alex, I'll take obscure, toxic p-block elements for 500!).  The questions are then written on 3x5 cards, with the name of the submitter on the back.  Depending on class size, the class is then broken into 2-4 teams.  The submitter of a given question is prohibited from participating when his or her question is posed.  All answers must be given in the form of a question.