The Mole in Chemistry: How do you determine the number of atoms or molecules in everyday items?

This page authored by Christina E. Stringer, University of South Florida. Activity authored by Rachel Wang, Spokane Falls Community College
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This material is replicated on a number of sites as part of the SERC Pedagogic Service Project


In this Spreadsheets across the Curriculum activity, students explore the concept of the mole as a measure of quantity. They build spreadsheets that allow them to convert between moles, grams, and atomic mass units for given quantities of everyday items, elements, and simple chemical compounds. At the end of the module students are asked to think about how they would determine the number of atoms in a paper clip. The module introduces the concepts of unit conversion, signficant figures, and scientific notation.

Learning Goals

Students will:
  • Create spreadsheets to practice using moles as a way to describe quantities.
  • Practice converting between moles, grams, and atomic mass units.
  • Practice thinking in terms of proper significant figures and scientific notation.
  • Determine the number of atoms in an ordinary paper clip.
In the process students will:
  • Become more experienced with unit conversions.
  • Increase their familiarity with significant figures and scientific notation.
  • Increase their problem-solving abilities.

Context for Use

This activity was designed for use in an introductory college chemistry course, but could easily be used in high school chemistry course as well.

Description and Teaching Materials

SSAC2005.QD461.RW1.1_Student (PowerPoint 1.5MB Aug1 07)
The module is a PowerPoint presentation with embedded spreadsheets as illustrations. If the embedded spreadsheets are not visible, save the PowerPoint file to a disk and open it from there.

Slide 6 of the module contains a link to an Excel spreadsheet that can be used by the students as a template for completing their work. The link can be activated by double clicking in the normal view (not in presentation mode).

This PowerPoint file is the student version of the module. An instructor version is available by request. The instructor version includes the completed spreadsheet. Send your request to Len Vacher ( by filling out and submitting the Instructor Module Request Form.

Teaching Notes and Tips

The module is intended for use as a stand-alone resource. It can be used as a lab exercise or homework assignment, or as the basis of an interactive classroom activity.


The last two slides contain an end-of-module assignment that can be used to examine student understanding and learning gains.

References and Resources

The WebElements website is a useful online periodic table can be used by students if one is not available in their classroom.