Investigating Patterns: An introduction to Mendeleev, periodicity, and the Periodic Table

Jennifer Hogan, Totino-Grace High School, Fridley, MN
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In this activity, students investigate a puzzle. They are given a set of cards with various properties. Each card has anywhere from 2 to 6 different properties depending on the level of the students and each set of cards has one or two cards missing. The object of the puzzle is to organize and group cards to look for a pattern in order to be able to predict the properties of the missing piece(s). Once the puzzles are completed the students learn about the process Mendeleev and other forerunners used in developing the first periodic tables.

Learning Goals

Learning goals:
This activity is designed for students to:
1. Work on their problem solving skills.
2. Understand and appreciate the thinking process that Mendeleev used when developing the first periodic table.
3. Understand and use patterns to make predictions and recognize how this relates to the periodic table.

Key Concepts:
Problem solving
Pattern development

Vocabulary Words:
-Periodic Table

Context for Use

This activity has been successfully adapted and used with students ranging from low level 9th grade science up through honors 12th grade students. It can be done in a classroom setting as long as students have a large space to work.

Introduction to the puzzle approximately 10 min.
The puzzle, depending on the level, usually requires about 30 min. of class time.
Puzzle follow-up and historical development 30 min.

Michael Offutt "Chemistry Song Bag" CD
Overhead cards (or other sample puzzle for introduction)
Puzzle Pieces (one puzzle for every pair) can be made with card stock or strips of sample paint colors

This activity is used as an exploration/introduction activity to Mendeleev, periodicity, and the Periodic Table. No prior knowledge is necessary.

Subject: Chemistry:General Chemistry:Elements & Periodic Table
Resource Type: Activities:Classroom Activity
Grade Level: High School (9-12)

Description and Teaching Materials

Students walk in to the classroom with Michael Offutt's song "Mendeleev" (Found on his Chemistry Song Bag CD) playing in the background on repeat.

As an intro activity, we look for patterns, discuss organization, and make predictions as a class. I do this with overhead transparency playing cards. The overhead cards are great because students are familiar with the properties of playing cards and the overhead feature makes it easy for all students to see what is happening. I pick out the kings, queens, jacks, tens, and aces of all four suits, Then I remove two cards out of this bunch. I scatter the leftover cards on the overhead and I ask for a volunteer to come up and move the cards into two groups. After they form their two groups, I ask them what property they used to separate the cards (black vs. red, face cards vs. non-face cards, etc.). I ask for a second volunteer to come up and use a second property found on the cards to organize the groups even further and then to describe their choice to the class (suit, card value, etc.). We continue with this pattern until we end up with the cards organized and ordered into columns and rows. At this point, it is clear that there are two missing pieces and I ask the students to describe the missing cards. After the cards are described, I remark on the fact that the organization and patterns they created helped them to make these predictions. I also point out that everyone may not have organized the cards in the same way and that people could have come up with the same predictions using other methods. ADAPTION: If you are working with a large class and you do not have overhead transparency cards you could make some using a copier or you could get across many of the same discussion points by describing the process of putting together a puzzle (starting with the edge pieces etc.) and predicting what missing pieces would be like (shape, color, design, etc.)

Next, I explain to the students that they will have the remainder of the class period to solve a similar, but more challenging puzzle with their lab partner. They will receive an envelope with a set of pieces inside which will have 1-2 missing piece(s) and their goals are:
o Describe/list all of the properties found on the pieces on their lab sheet (for the playing cards these properties were things like color, suit, and value)
o Organize the set of pieces so that a pattern develops for each of the properties
o Predict the properties of the missing piece(s) and describe them on the lab sheet
*For lower level classes, I made a puzzle using pieces with two properties: color and number. I used the paint sample strips that you can get at a hardware store to get shades of colors and then wrote numbers on the strips with a pattern (any mathematical pattern will do). For example: the paint strips can go in ROYGBIV and light to dark within each color and the numbers could follow a pattern of always adding the same amount from one row to the next and always subtracting the same amount from one column to the next. Depending on the level of the class and the amount of time the students had to work I decided how many pieces the students would be given and how many pieces would be missing. For higher level classes, I made a puzzle using card stock and pieces with six different properties: color, a whole number on top, a decimal number on the bottom, star stickers in the middle, hole punches in the middle, notches cut out of the side. There are pre-made puzzles like this that you can purchase and some that are even made using actual properties of elements...depending on your budget and what direction you want your discussions to head.

The following day, the students walk into the classroom hearing the "Mendeleev" song, the lab sheets are returned, and the discussion begins. We talk about the history of the Periodic Table leading up to Mendeleev. We also compare the process the students used when solving their puzzles to the process that Mendeleev used in creating his table. We discuss the predictions Mendeleev made and why his work was so amazing. We also begin to discuss the concept of periodicity and the usefulness of the Periodic Table.

Teaching Notes and Tips

The big thing to remember with this activity is that it is important to monitor frustration level. The puzzle should challenge the students, but not completely discourage them. It is great for them to feel some level of frustration when attempting the puzzle because it really helps them appreciate the historical work of Mendeleev and the other forerunners. However, it is the teacher's job to help the students along and keep the frustration level in check while allowing students to feel the sense of accomplishment gained by solving a difficult puzzle on their own.


The teacher will check to make sure students find and list on their lab sheet all of the properties the puzzle pieces contain before they try to piece the puzzle together. The teacher will walk around and monitor the puzzle solving process. The teacher will be able to determine if students have properly solved the puzzle by their description of the missing piece(s) on their lab sheet. The teacher will discover student understanding of the historical process and the modern periodic table through class discussion and individual completion of homework questions.


9-12.I.A.2,3,5 Scientific World View
9-12.I.D.2 Historic Perspectives

References and Resources