Summary

In this demo, students will learn the difference between observation and inferences.

Grade Level

High school

Objectives

By the end of this lesson, students should be able to

• How important it is not to jump to conclusions.
• That making careful observations is an important skill.

Chemistry Topics

This lesson supports students’ understanding of

• Observations

Time

Teacher Preparation: 5 minutes

Lesson: 20 minutes

Materials

• String cheese (any white variety)
• Knife
• Almond sliver
• Lighter

Safety

• Always wear safety goggles when working in a chemistry lab.
• Always use caution around open flames. Keep flames away from flammable substances.
• Food should never be consumed in the lab. Carry out this demo in a classroom setting away from chemicals.

Teacher Notes

• Before class begins, take a piece of string cheese and cut it into small pieces to resemble a birthday candle.  Insert an almond sliver into the top so it resembles the “wick” of the candle. Keep “candle” hidden until needed.
• Start explaining to students the difference between observations and inferences. Instruct the students to take out a piece of paper and write down their observations. Then take out the “candle,” light it, and encourage the students to take careful observational notes on the item. Walk around the room and then casually blow it out. Ask the students to read aloud some of their observations. Most likely, someone will say it’s a candle.
• After solidifying the notion that it’s a candle around the room, eat the so-called candle.  Be amazed as your students shriek in horror. If you are brave enough, the shock value of this demo could be enhanced by placing the lit “candle” into your mouth before blowing it out.
• Finish off by explaining the differences between observation and inferences and how important it is for scientists to take accurate observational notes and not jump to conclusions as they quickly did.