Electron Configurations

Other Chemistry lessons: Add 'Em Atom and Molarity Jeopardy
  • Subject Area: Chemistry
  • Age or Grade: Juniors/Seniors
  • Estimated Length: 80 minutes
  • Prerequisite knowledge/skills: Students have learned some of the basics of the periodic table (groups, periods, atomic number, etc) and have learned about electron shells.
  • Description of New Content: Introduce electron subshells.
  • Goals: Students will learn how to write electron configurations.
  • Materials Needed:
    • Computer
    • Projector
    • clean periodic table
    • markers (4 different colors)
    • slides
    • worksheets (slides 7-10)
  • Procedure:
    • Opener:
      1. Pass out a clean periodic table.
      2. Review with students that rows are called periods and are equal to the # shells and columns are called groups and are equal to the # valence electrons. Have students label their periodic table according to slide 1.
    • Development:
      1. Introduce subshells s, p, d, and f. Have students color code their periodic table according to slide 1. Ask students to name an element with a subshell of s, p, d, and f.
      2. Pass out 1st worksheet (slide 7). Introduce how to write an electron configuration (explain the large number is the row # = # shells, etc according to slide 2). Challenge students to determine which element has a 1s1 configuration.
      3. Pass out 2nd worksheet (slide 8). Explain to students that if they are asked to write electron configuration, answer these 7 questions. Have students complete this example on their own. Go over the answers (slide 3).
      4. Pass out 3rd worksheet (slide 9) for more practice. Answers on slide 4.
      5. Pass out 4th worksheet (slide 10). Explain to students that electron configurations do not go in "order". Rather, it goes in order of the periodic table from left to right, top to bottom (don't forget the lanthanoids and actinoids). Slide 5 shows a diagram of the order. Have students draw arrows on their worksheet and rewrite the full electron configuration.
      6. Use slide 6 to explain why writing does not go in order (subshells d and f are special). Have students label their periodic table.
    • Closure:
      1. Review the 4 subshells.
  • Evaluation: Ask students to pick another element and write the electron configuration (tell them to pick one near the top of the periodic table--it's easier).
  • Extensions: Students can pick a lanthanoid or actinoid element.