Beacon Lesson Plan Library

Physical or Chemical? That is the Question

Ann Kennedy

Description

Students use the five Web World Wonders camera sites to locate and identify examples of physical and chemical changes.

Objectives

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

Materials

-Reclosable plastic bags
-Items from school yard
-Tongs
-Garden gloves
-Magic markers
-Internet accessible computers
-Web World Wonders (click online 'Web Cameras')
-Paper for sketching or printing
-Transparencies for final assessment-optional
-Overhead if transparencies are used in final assessment

Preparations

1. Make arrangements for taking students on a campus scavenger hunt
2. Make sure there is Internet computer access
3. Purchase reclosable plastic bags for scavenger hunt items and gather other items.
4. Make pictures from camera sites for final evaluation. (You may want to put these on transparencies). Collect campus items for assessment.
5.Designate student groups for each camera site.

Procedures

Note: Before undertaking this lesson, students should have basic computer skills and a knowledge of the meaning of the terms ' physical and chemical changes'.

1. All students are asked to take out a sheet of paper. They are then asked to change the paper physically. In the discussion that follows about physical change, the students are then asked to write in their own words what is involved in a physical change and what clues to look for. These paragraphs should be shared aloud and the teacher should informally assess student understanding. Then the students are asked how they would change the paper chemically. After discussion about chemical changes the student writes in his/her own words how an object could be chemically changed and the clues that allow one to know the change has occurred. These paragraphs should be shared aloud and assessed informally for student understanding of a chemical change and its clues.

2. Inform students that they are going on a scavenger hunt. They will collect items from around campus ( stepped on pine cones, pieces of paper, pieces of plastic, etc.) during a 10-minute scavenger hunt. Items should reflect a chemical or physical change according to the discussion that has just taken place. Items should be picked up with the tongs or by students wearing gloves. The items are placed in the recloseable plastic bags and taken back to class. With a magic marker, label the bags and items with a letter. On paper, the students classify their objects as to whether the items exhibit a physical or chemical change. (Some items may show both physical and chemical changes). Be sure that students include the clues in the classification process.

3. Divide students into 10 groups of 3 students per group. (two groups per camera site) . Using the Web World Wonders camera sites: Wakulla Springs, Saw Grass Lake, Pigeon Key, Six Mile Slough, KSC-NASA -each group will look at a location and identify examples of physical and chemical changes. The students have to justify their choices in designating the change as physical or chemical. They must use and identify clues.

4. Each group sketches or prints 5 examples of each classification that they are identifying . The students list clues that justify their choices in designating the change as physical or chemical.

5. Each group then shows their favorite picture or sketch to the class . The class then determines if the picture is an example of a physical or chemical change. The group gives its list of clues and their results to see if there is an agreement with the groupís choice and justification. Class members need to come to consensus before the next group shares.

6. Administer assessment by using 10 camera site pictures and 10 campus items. The students have to tell whether the item is an example of a physical or chemical change and list 2 clues to justify their classification for each item .

Assessments

To evaluate the students, select 10 pictures from the 5 camera sites and 10 items from the campus scavenger hunt that represent physical and chemical changes. The student must correctly identify the physical or chemical change and correctly list clues for each of the changes in the items shown in the pictures. Students who are not able to determine if the picture shows a chemical or physical change and identify the corresponding clues, should receive formative feedback and have additional opportunities to make the identification. These students could be paired with students who show mastery of the benchmark in order to receive practice.

Extensions

Before undertaking this lesson, students should have basic computer skills and a knowledge of the meaning of the terms ' physical and chemical changes'.
Extend this lesson with the addition of a lab involving chemical and physical changes such as baking soda and vinegar, burning paper, crushing chalk or Alka Seltza, etc.
This lesson could be a lead-off for going into weathering agents and erosion.

Web Links

Web supplement for Physical or Chemical ? That is the Question.
Web World Wonders

Return to the Beacon Lesson Plan Library.