Below are a number of activities that you can perform offline to complement the contents of this module. Crossword Puzzle of Keywords and Concepts How Does a Pencil Write? Building a Structural Model of C60   The online activities below are embedded within the module, here is your direct access to them. Determining Avogadro's Number using graphite Calculating the mass density of diamond, graphite, and buckminsterfullerene using crystallographical data Interactive visualization of the graphite crystalline lattice