Education Technology

Chemistry: Writing Chemical Formulas

by Texas Instruments - Simulation Lesson


  • Students will understand that the chemical formula identifies each constituent element by its chemical symbol.
  • Students will understand that a subscript after the chemical symbol indicates the number of atoms of each element found in each discrete molecule of that compound.
  • Students will recognize that the valence of an element determines the ratio that atoms will combine with one another to form a neutral compound.
  • Students will understand that atoms always combine with one another in simple whole number ratios.


  • cation
  • anion
  • ionic compound
  • ionic charge
  • valence

About the Lesson

This lesson involves students practicing writing chemical formulas for ionic binary compounds. The activity consists of four parts:

  • Students will write chemical formulas given a cation and an anion.
  • Students will determine the charge of a transition metal given a formula of a compound. Students will write chemical formulas given the name of a compound.
  • Students will name a compound given its formula.
As a result, students will:
  • Reinforce understanding of the concept of ionic charges necessary to write the chemical formula of ionic compounds.
  • Recognize that the valences of the elements determine the ratio of the elements in a compound