Atomic BB's: A Particle Model of Metals

The Materials Science and Technology Teacher's Workshop (MAST) provides this experiment on the basic particle model for metals. The activity uses Bbs in a Petri dish to simulate the formation and movement of metal atoms as well as show dislocation and vacancy movement. Students will fill a Petri dish with Bbs and pretend the Bbs represent atoms in a metal. The movement of each Bb represents heat and this causes various defects in their crystal structure. By doing this, students will observe defects such as vacancies, grain boundaries and dislocations. The lesson includes a step by step explanation of the laboratory procedure and discussion questions. The exercise should take about 40 minutes of class time to complete.