Apologia Chemistry: Module Eight Tips

Today I wnet over the Periodic Trends with the kids in my Co-op class.  Let me share how I approach this instruction.  Last time, we spent time explaining and practicing electron configurations.   Keep a copy of the notes or sample configurations out, especially Hydrogen to Argon.  Just a note-the short-hand version is best to display the valence electrons for this lesson.  Next, have a copy of a Periodic Table with  Electronegativity and charts with Periodic Trends. (This one has a difference perspective, which can help.)

Now, help the kids see the patterns.  I use Electronegativity to explain the concept of periodic trends or patterns in the Periodic Table.  Linus Pauling was a professor and used a GPA scale to compare an element's ability to grab electrons.  My kids study this trend first, particularly Group I and Group 7 elements.  Periodic Trends are described going from left to right on the Table and top to bottom in each group, typically involving only 'main group' or representative elements.

Once the class has the idea of a trend, each child or group receives a different trend: electron affinity, metallic and nonmetallic character, first ionization energy, atomic radius, ionic radius, density, melting point, boiling point, and electronegativity.  I chose metallic and nonmetallic character, atomic radius, and first ionization energy this time.  When I have a large group, pairs of students get a trend to model.  The team must define the trend, describe the trend, and defend their model.  When I have a big class, I set out a variety of materials for their models: paper plates, reaction plates, toothpicks, straws, markers, etc.  This time, I elected to have the Co-op use the straws, reaction plates, and clay.  I did insist they measure the straws to make them proportionate.

We did not have time for the Periodic Tend Game; but I did show the kids how to play.  Basically, you throw a die on a Periodic Table.  When it landed, I asked the kids to estimate the element's electronegativity, relatively high or relatively low, and explain.