Introduction to Periodic Table

One of the units that I teach in Physical Science is all about using the periodic table. It a basic science unit, that most general science teachers are doing. The thing that I have always struggled with is making the unit interactive and interesting.

In years past I have had students organize random objects (such as rubber stoppers of different sizes, materials, holes, etc) into a periodic pattern. This had some positives, but did not really introduce the structure of the periodic table, and how it follows a periodic pattern.

This year I did some research and found an activity that it looked like lots of people in my situation we doing: The Alien Periodic Table. Really it is a guise for our own periodic table, but the elements are given alien names. The purpose of the activity is to get kids looking at the elements of an alien world, much like Dmitri Mendeleev did back in the 1860’s.

Students were given 40 elements to organize (the first 40 by atomic number, not counting the transition metals) and were told the atomic mass and basic properties of the elements. The names eye changed, the masses multiplied by a random value, so that they would not be able to match it up to our own table easily. Students were then given 2 class periods to organize a table.

A lot of groups started off going down the right track, and were organizing elements into groups by similar properties. This was fantastic! At this point I was extremely excited to see where things were going. Unfortunately, they did not go in the direction I expected.

Kids went from the groupings they established, but when it came time to make an actual table like Mendeleev did, they struggled, some to a grinding halt. Many students struggled with the concept of creating a table that followed a patter both vertically and horizontally. Even though we discussed the idea of using atomic mass and properties, trying to make this basic construction was an enormous challenge.

My basic thoughts on this are:
1) this task is not beyond the student ability.
2) the struggle may result from this being the first time they have encountered the idea of a periodic pattern.
3) I think it also speaks volumes as to what kids actually think or understand about the periodic table. They have all had a basic introduction to it, but they are not taught at earlier ages what the table actually represents.

Now what? I’m not sure, I’m still processing the information. One thing I know, is that this activity,though it did not accomplish what I was hoping for, told me a lot about what my students knew about the periodic table. Or rather, what they didn’t know. It also introduced a level of dissonance to their understanding. I think they were genuinely made uncomfortable by the struggle they had in making their own table, and as such are going to be more susceptible to learning about how it is really constructed, and the information that they will be asked to learn.

That’s the hope any ways.