Bring students to your school's computer lab to explore Internet-based atom games, such as those available on the NeoK12 site. This site allows students to label the diagram of an atom, put together puzzles of atoms, or play games that focus on the structure of atoms. There are a number of atom-related quizzes available through several different science and review sites. Students can test themselves or their friends using these sites without having to worry about being graded.
Set up an atom trivia game in your classroom. Trivia can take the form of the popular "Jeopardy!" game show, or as a general question-and-answer game. In any event, create different categories of questions, such as the structure of an atom or the atomic numbers of different elements. Assign points based on the difficulty of the question. Students can play this game on teams or as individuals.
Create a word find puzzle where the students have to find different phases related to the study of atoms and atomic structure. Another option is to scramble up key terms and require students to unscramble the message. Crossword puzzles can be educational as well, and can provide a bigger challenge. Instead of just locating words, students will have to know the definitions and understand the clues in order to complete the puzzle. Puzzles can be done in class, or passed out for students to complete as extra review on their own time.
Bring in supplies that students can use to build their own model atom, then host an atom-building contest in your classroom. Good materials include construction paper, Styrofoam balls and yarn. Let students compete by themselves or divide them up into groups. Assign everyone the same atom to build. See which individual or group finishes first. Award that person or persons a small prize, such as a no-homework pass or extra points on the examination that covers atoms.