The mole concept is fundamental to chemistry. Students learn that a mole is a counting unit used to bridge the atomic and macroscopic scales. Mole calculations are important in areas such as biomedical research.
Students determine the scale of the relative masses of nails as an analogy to the atomic mass scale.
The relative mass of large to small nails can be determined by weighing the masses of groups of 100 nails. Have the students assign the mass of one group of nails as 12 units on an arbitrary scale and determine the relative mass of the other group of nails. Provide students with materials such as aluminum foil, copper tubing, iron nails, and table salt so they can visualize the volume associated with the molar mass of the element or compound. When students work with the relative mass of nails or other objects, check to see that their measurements are precise and are given as correct ratios of their standard. Have them provide brief written explanations of how their activity illustrates the use of the atomic mass scale.