Summary

In this activity, students will use the periodic table, combined with math and logic to solve several chemistry themed pyramid puzzles. In a traditional pyramid puzzle, there is a relationship between the numbers, which is used to determine the missing numbers. In all of these chemistry pyramids, each element symbol is determined by the sum of the two atomic numbers of the elements directly below it. Students are challenged with determining the missing element symbols in each puzzle, but first must use a periodic table to find the atomic number for each element symbol appearing in the puzzle. This activity is a fun challenge for students and provides the opportunity to strengthen logic and reasoning skills.

Grade Level

High School and Middle School

NGSS Alignment

This activity will help prepare your students to meet the performance expectations in the following standards:

• Scientific and Engineering Practices:
  • Using Mathematics and Computational Thinking

Objectives

By the end of this activity, students should be able to:

• Determine the atomic number of an element, given the element symbol.
• Use logic and reasoning skills to properly solve a math-based puzzle.

Chemistry Topics

This activity supports students’ understanding of:

• Periodic Table
• Elements
• Atomic Number

Time

Teacher Preparation: minimal
Lesson: 15-20 minutes

Materials

• Student Handout
• Periodic Table

Safety

• No specific safety precautions need to be observed for this activity.

Teacher Notes

• This puzzle was created to appear in the November 2023 ChemFun section of Chemistry Solutions.
• There are eight puzzles included with this activity. Puzzle 1 is the easiest, while they progressively get more difficult as students move towards puzzle 8.
• Below are some hints for helping students successfully solve these puzzles:
  • First students should determine the atomic numbers for each of the element symbols shown in the puzzle.
  • Start by solving smaller pyramids inside of the larger pyramid by looking for groups of three that contain only one missing number.
  • All of the pyramids contain positive, whole numbers that correspond to an element’s atomic number.
  • Numbers may be repeated within a pyramid.
  • The more difficult pyramids may require some guess-and-check in order to solve. Suggest that students use a pencil when attempting to solve these.
• An Answer Key has been provided for teacher reference.