Path to the Periodic Table
This activity allows students to re-create the thought process that Dmitri Mendeleev and Julius Lothar Meyer went through to devise their early periodic tables. The students are given cards (provided at the end of the teacher activity page), each with the name of an element, its symbol, and some properties. The students are then asked to sort the elements into a table of some sort, in any way that makes sense to them. In arriving at arrangements similar to those devised independently by Mendeleev and Meyer, they will come to a greater understanding and appreciation of how the periodic table is organized and of the information it contains.
The activity is carried out in three steps. In the first step students are given only cards of elements known to Mendeleev and Meyer. Students should conclude from gaps in their arranged tables that unknown elements await discovery. In the second step students are given cards for gallium and germanium, predicted by Mendeleev based on gaps in his table. Students are asked to place them in their tables. In the third step students are given cards for noble gases, unknown to Meyer and Mendeleev, and not predicted based on their tables. The students are then asked to find a way to include the noble gases in their tables.
Student Ability Level and Grouping
This activity is appropriate for high school introductory chemistry students or ninth-grade physical science students. The activity is best carried out by students working in groups of three or four.
Expected Student Background and Skills
Students should have an understanding of elements and compounds, as well as of atoms and molecules. They should especially understand the atomic-level definition of an element as a substance made of only one kind of atom. It is also important that students have an understanding of atomic masses and atomic numbers. Students should also have a basic understanding of formulas of compounds.
Time and Materials Required
This activity can be completed in 20 to 30 minutes. No special materials are needed.
- Students will gain an understanding of how the periodic table is organized.
- Students will gain an understanding of how the periodic table was developed, including an understanding of how scientific ideas change as new evidence becomes available.
- Students will gain an understanding of the kinds of information contained in the periodic table and how to “read” the table.
National Science Education Standards
Science as Inquiry
- Abilities necessary to do scientific inquiry
- Understandings about scientific inquiry
- Structure and properties of matter
History and Nature of Science
- Historical perspectives
- Nature of scientific knowledge