Crystal Gym

Several things that we use in our daily lives like graphite in pencils, quartz in clocks and common salt are crystalline substances. Crystal posses a high degree of orderliness in the arrangement of atoms, molecules or ions that gives them a definite structure. The structure, however, depends on the composition. Remarkably, the smallest pieces as well as the largest one will have exactly the same structure. This is evident from the model of the Crystal of common salt or sodium chloride you see here. The yellow sphere represents sodium ion and the green sphere represents chloride ion.