##### My Notes

##### Categories

In this activity, students self-organize according to periodic trends. I print out the attached cards onto card stock (each page will contain two) and hand them out to the students (one to each). Generally, we go outside and I shout out periodic trends (i.e. size, polarizability, ionization energy, Z_{eff} etc.) and the students run to get in line in the correct order. I have a bell which I ding if correct, and a buzzer that I sound if incorrect. If incorrect, they have to try again. Students can "shout out" to their peers suggestions as to the ordering. After the students are in the correct order (and sometimes when they are in the incorrect order if I see a consistent misconception in their thinking) I ask at least one student the reason for their chosen ordering. The "Instructor Notes" describe how I use this activity in General and Inorganic Chemistry and include a discussion of some common student misconceptions.

This activity typically takes about 10-15 minutes at the end of the lecture period in which we review periodic trends. It can be easily modified for classes of different sizes by adding more atoms and ions.

Attachment | Size |
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Athletic Periodic Trends Instructor Notes.doc | 44 KB |

atoms.doc | 22 KB |

A student should be able to apply his/her knowledge of periodic trends to participate in ordering a list of atoms and ions according to a given trend and should be able to explain the reasoning behind her/his choices.

The attached atom cards printed on card stock as well as a buzzer and a bell (or two other sound making devices).

The students really like this! Especially if they get to go outside (though running up and down the chemistry hallway is fun, too)!

#### Evaluation

**Expert:** The students get all periodic trends correct, can articulate all conflicting trends and make reasoned judgements as to which dominates, appreciate subtleties (size effects larger toward the left). Can articulate correct reasoning for their orderings even in complex situations. For example, can rationalize a diagonal trend.

**Proficient:** Students understand the primary periodic trends in isolation. Have some difficulty with conflicting trends. Subtleties essentially absent. Can articulate correct reasoning for their orderings in simple situations and inconsistently in complex situations. For example, can rationalize horizontal and vertical trends.

**Apprentice:** Students can arrange atoms/ions in primary trends correctly but do not articulate correct reasoning for their orderings. For example, trends may be memorized (size goes up as you go down).

**Novice: **Students can not consistently arrange atoms/ions in primary trends without coaching and cannot articulate correct reasoning for their orderings. For example, may know what happens to size as you go up and down but not left to right.

Students generally do very well at ordering atoms according to "simple" trends (like atomic size). Less familiar trends (polarizability, for example) or trends including ions (particularly mixed groups of atoms and ions) students seem to find more difficult.

^{2+}, Pb^{2+}, Pb^{4+}, Cs, Ge, Hg^{2+}, Ba, Ta, Ce and Eu. I never had all the cards out at once, but continued to change things up to get them to think about different nuances of the trends.I did this in my general chemistry I class with about 80 students after covering periodic trends. I requested volunteers (5 - 6) and they took turns at the front of class to arrange themselves in whatever trend was given. At first, I did it somewhat like a game show. However, after the students got the hang of it I took somewhat of a backseat (except for explanation of course!), and those in the audience were helping the volunteers. They appeared to have fun with it, and it gave a nice break from the typical lecture.

I ran this activity with my general chemistry class this fall. The class is made up of three sections of 24 students, so I had them divide up into their sections and gave each of them one of the 24 atoms/ions from the activity. I then posted the particular parameter (i.e. - 1st row neutral atoms) and the trend I wanted them to sort themselves by (i.e. - atomic radius) on the projector. I ran it as a competition to see which section would get the correct ordering first, with everyone in the section working together to get the answer right. They seemed to enjoy the activity, but it was a bit chaotic. I will probably use smaller groups next year to ensure that everyone is participating fully.

I used this activity as a review exercise in my 300- level descriptive class just

beforewe discussed periodic trends. I had 25 students, so I simply distributed the element/ion cards randomly and formed changeable groups by calling out which cards I wanted in a particular group. I made the students who were not currently in the active group decide when the active group was correct (I had ultimate say over this.. ie I would tell them if the audience if they were correct or not).I think my students had a good time with this activity, and a lot of good discussion was generated because their first attempts at ordering were all ( 100 %) incorrect. In all cases the active groups had to rearrange themselves- in other words, retention of knowledge of periodic trends from general chemistry was flawed. On the other hand, I think the discussions forced recall of some of the material.

I have heard/seen colleagues use sound effects and maybe that would have added some fun to it, but I did not do that (lack of preparation time).

I used this again today, and added a twist by asking them to self identify into groups, e.g. first row transition metal ions, alkali metals, etc.

fun was had by all.

I used an app called The Ultimate Buzzer on my iphone... great sound effects.

I did the first three on the gen chem list this morning (saving the rest to review before the test) thinking they would be quick and easy. Wrong again. It almost seemed like they knew the trend, but couldn't figure out how to line up. So I think there was some good "spatial relations" learning going on. I also made them use their bodies (and a chair) to show "bigger" and "smaller." That was very helpful in visualizing the trend. I learned that from Lori, the LO author.

I used the first four sets on the general chemistry list (all atomic size trends) in my general chemistry class. This needed a little over ten minutes of class time. The p-block set was the most challenging and took the most time for the class to figure out correctly. The students had trouble knowing what to do when the atoms were from different periods. Next time, I might alternate atomic size and ionization energy sets so that we get some of both.