Summary

The students will work in cooperative groups to construct Bohr models of "mystery" elements and record missing information about each element. Students will also create a new "mystery" element card for a classmate to analyze and determine its identity.

Grade Level

Middle or High School

Objectives

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

• Correctly construct and interpret a Bohr model for an atom.
• Describe the structure of an atom including its mass, its electrical charge, and subatomic particles.
• Determine the quantity of electrons, protons and neutrons in an atom, given essential information.
• Identify that protons determine an element’s identity.

Chemistry Topics

This activity supports students’ understanding of

• Atomic Structure
• Subatomic particles
• Atomic Mass
• Atomic Number

Time

Teacher Preparation: 30 minutes

Lesson: 40 minutes

Materials

• Metal pizza pan with 3 orbital shells and nucleus drawn on it (1 per pair of students)
• Metal cookie sheet divided into three sections to store magnetic beads (1 per 4 students)
• Colored magnetic beads (three colors for the three subatomic particles)
• Laminated “Mystery” Element cards (1 set per 2 students)
• Laminated Periodic Table (1 per 2 students)
• Student Page
• Index Cards (1 per student)

Safety

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

Teacher Notes

• This activity works well with four students sitting at a group table. Each student will work with a partner. Each set of partners will have one laminated periodic table, one metal pizza pan, and access to the cookie sheet with magnetic beads (shared between two sets of partners). Each student will have a student page to record their data.
• The metal pizza pans, cookie sheets, colored beads, and magnetic strips can be purchased at a dollar store for minimal cost. The materials can be stored and reused each school year.
• Advance Preparation includes:
  • On each metal pizza pan, use a black sharpie marker to draw a solid black circle in the middle to represent the nucleus and draw three orbital shells.
  • On each metal cookie sheet, use a black sharpie marker to divide the cookie sheet into three sections. Label one section “protons”, one section “neutrons”, and one section “electrons”.
  • Adhere a piece of adhesive magnetic strip to each colored bead.
  • Sort the colored beads onto the metal cookie sheet with one color for each of the subatomic particles.
  • Print and laminate the “mystery” element cards (1 set per 2 students).
  • Print and laminate copies of the Periodic Table of Elements.
  • Print and copy the Student Page.
• Teachers may use the “mystery” element cards provided with this activity and/or they may make additional “mystery” element cards.
• Student groups will work on the same set of “mystery” element cards so the teacher may assess student understanding during the activity and correct any misconceptions.