Overview

Students are provided with a set of cards showing different combinations of possible interactions between positively and negatively charged electrons. Students sort the cards to show which cards are the most accurate and which are inaccurate, then rework the inaccurate diagrams to make them accurate.

What you'll need

Handout of Charge cards and scissors or already cut up set of cards, one set of 12 cards per pair of students

Instructions

1. Organize your students into pairs. Ask groups to think of three statements to explain the relationships between positively and negatively charged electrons. Invite groups to share their statements with the class. 
   • If necessary, remind them of the basic principle that like charges repel and opposite charges attract.
2. Provide each group with a set of Charge cards. Briefly explain that each card shows a different interaction between positively and negatively charged materials. Explain that their challenge is to sort the cards into two categories: cards that accurately show the relationships between charged materials, and those that inaccurately show the relationships. Give groups time to sort their cards.
   • Consider inviting groups to visit other groups to hear their thinking and see how they’ve sorted their cards.
3. Invite groups to share their decisions and thinking with the class. 
4. Ask groups to take the cards that are inaccurate and modify them so that they accurately reflect the relationships between positively and negatively charged materials. 
5. Invite groups to share the original inaccurate and the reworked diagrams with the class and explain their changes.