## Inquiry-based lesson: Periodic Table

This Thursday I attempted to do an inquiry-based lesson with my students on the organization of the periodic table of the elements. Knowledge of the table and the atoms/elements that compose it are a part of the next checkpoint test for the students so I hoped that adapting my lesson to their schedule would keep them on track. A large portion of the 90 minute class periods required me to lecture about the basic structure of atoms, how varying the numbers of sub-atomic particles resulted in discrete elements, and how the periodic table is organized by atomic number, period (row), and group (column) because the students had no previous experience with the material. I thought, mistakenly, that my ‘problem’ would be very simple. I split the class into six groups, and gave each a bag of twelve individual LEGO pieces. Each group’s objective was to decide upon an organizing scheme for their LEGOs, draw a table, and then be able to defend to other groups why their ‘periodic table of LEGOs’ made sense to them.

I envisioned the students easily grouping their pieces by color, size, or shape (one aspect of a 2-factor table–as opposed to a 1-factor table = list!) then perhaps having some difficulty choosing a second organizational variable. For example, a table could be organized by color (rows) and then piece size (column), such that an example row would be red pieces arranged from smallest to largest (tracking left to right). Apparently, I did not fully comprehend the way their brains worked through problems. Of 18 groups total, only two independently came up with a valid table scheme. The rest either tried to organize their pieces into undefinable groups OR, strangely, tried to link their LEGOs together to create the shape of the actual periodic table of the elements. Weird! Reflecting on the problem later, I think the hardest part of the exercise was an assumption that I never even considered. I was asking them to categorize the LEGOs into groups. Their brains insisted on them actually putting the LEGOs together (linking them) to build a shape. I guess I should have seen that coming—why would one do anything with LEGO pieces other than build things?