Beacon Lesson Plan Library

Physical/Chemical Properties of a Burning Candle

Jeri Martin

Description

What happens to the physical and chemical properties of a candle before and after it is lit? Students investigate these properties by conducting the Burning Candle activity.

Objectives

The student determines the physical properties of matter that can be observed without altering the substance (for example, mass, volume, boiling point, density).

The student knows how to use clues (for example, change in color or form) to determine whether a change is chemical or physical.

The student uses appropriate procedures for safety in the classroom, home, and community.

Materials

Per group of 2 students:
-Candle (1520 cm in length)
-Candleholder
-Safety goggles
-Stopwatch
-Balance (triple beam or electronic)
-Metric ruler
-250mL beaker
-Match

For each student:
-Burning Candle Lab (See Associated File)
-KWL Chart (See Associated File)
-Laboratory Rubric (See Associated File)

Preparations

1. Make copies of the KWL Chart, Laboratory Rubric and Burning Candle Lab for each student. (See Associated File)
2. Prepare equipment for lab activity.
3. Gather materials. Note: For candles (paraffin wax C20H42), the best price I have found is at dollar stores 12 for $1.00. The best price I have found for candleholders is also at dollar stores 2 candleholders for $1.00.

Procedures

1. Give students a copy of the Laboratory Rubric. (See Associated File) Discuss the rubric with the students explaining, even though this lesson is concerned with physical and chemical properties, that safety procedures and proper use of lab equipment is expected.

2. Give students a copy of the KWL Chart for Physical and Chemical Changes. (See Associated File)

3. Discuss with students the K (what do you KNOW) and W (what do you WANT to know) from the chart. Note: The L (what did you LEARN) will be completed at the end of this activity.

4. Have students complete and turn in the Burning Candle Lab. (See Associated File)

5. Have students complete the L section of their KWL Chart and turn in.

Assessments

1. The Laboratory Rubric is marked as students go through the lab.
2. The KWL Chart and Burning Candle Lab will be collected. The entire Burning Candle Lab and the L section of the KWL Chart will be assessed. (A Teacher's Copy of the KWL Chart is provided in the associated file.)

Extensions

1. Repeat the lab, but use other size candles (birthday, votive, etc.) and/or candles made from substances other than paraffin (i.e., bees wax).
2. The procedures could be modified to allow it to be used as a cooperative group activity for ESE/ESOL students or if there are not enough supplies for two students to have a setup.

Web Links

Web supplement for Physical/Chemical Properties of a Burning Candle
Utah Science

Attached Files

Handouts and activity sheets necessary to accomplish this lesson.     File Extension: pdf

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