In this lesson, students learn to distinguish between physical and chemical changes. At the end of this lesson, students should be able to define physical and chemical changes, as well as give examples for each.
Begin this lesson by showing students a sheet of paper. Ask students, “How can I change this sheet of paper?” Make a list of students’ suggestions on the board. Students should have examples, such as tearing the paper, crumpling the paper into a ball, or burning the paper. Explain to students that the list of changes they just created can be divided into physical and chemical changes.
Provide the purpose for the lesson by saying, “Today we will be learning about the two types of changes that you can make to matter: physical and chemical.”
Show a video on chemical and physical changes: https://www.youtube.com/watch?v=qqqmFFCwd7k&feature=related
Provide the students with an informal quiz on common physical and chemical changes (S-5-1-2_Changes Quiz.doc). Have students take the quiz and review answers when they are finished. Address any questions students may have before moving on to the next section.
Have students turn to their Matter Vocabulary worksheet (S-5-1-1_Matter Vocabulary Worksheet.doc) in their science journals. Students should fill in the two new vocabulary terms: physical change and chemical change. Give students about 2–3 minutes to brainstorm a definition for each of the terms. After giving students time to brainstorm, ask volunteers to share their answers. Then introduce the correct definitions for each term. Give assistance to students when creating a sentence for each term.
After completing the vocabulary for the two terms, return to the list on the board of the changes they could make to the sheet of paper. “Now that we have reviewed physical and chemical changes, group this list we made into physical and chemical changes. Who wants to volunteer to put a circle around the examples of chemical changes and to put a square around the physical changes?” Allow various student volunteers to come up to the board and group the changes into physical and chemical.
Next, give each student a copy of the Chemical or Physical Changes Worksheet (S-5-1-2_Chemical or Physical Changes Worksheet and KEY.doc). As students are working, walk around the classroom and assess how students are answering each question. Review the answers when students have finished. When checking the last two questions on the worksheet, have volunteers share their examples for chemical and physical changes. Record their examples on the board using a T-chart format, like the one below.
|
Physical Changes
|
Chemical Changes
|
Hand out to each student a copy of the Comparison of Physical and Chemical Changes Worksheet (S-5-1-2_Comparison of Physical and Chemical Changes Worksheet and KEY.doc). Give students about 15 minutes to revisit and review the information learned throughout the lesson. Check for students’ understanding after the entire class has completed the worksheet.
Begin the next activity by giving each student a sheet of construction paper and markers. “You will be creating a Chemical/Physical Change Poster for three different objects in your home or outside of the classroom. Walk around the classroom and choose which three objects you want to use to complete this assignment.” Give students about five minutes to identify three objects in the classroom that they want to feature on their poster. Allow for students’ creativity in the format that they use for their poster. Each student should have a picture of the object first. Then the student will need to show a picture of a chemical change and a picture of a physical change for each of the three classroom objects that they chose. Students can either draw their pictures or they can print them from the Internet. Allow students about 20 minutes to begin working on their posters in class. Walk around the classroom to answer any questions students may have about the assignment. Have students complete working on their posters for homework.
As a closing activity, give each student a copy of the Writing Activity Worksheet (S-5-1-2_Writing Activity Worksheet.doc). Tell students that they will be asked to give a written response to the following question: “What are the differences between chemical and physical changes? Give two examples of chemical and physical changes that you notice in your everyday life.” When students finish, have them share their responses with the rest of the class.
- Closing Activity Writing Rubric
|
Score
|
Expectations
|
|
2
|
Student clearly explains the difference between chemical and physical changes. The student gives two examples of each type of change. Student has excellent use of grammar and punctuation.
|
|
1
|
Student explains the difference between chemical and physical changes. The student gives one, or no, examples of each type of change. Student has satisfactory use of grammar and punctuation.
|
|
0
|
Student does not understand the prompt or does not attempt to answer it.
|
Extension:
-
Take students to the school library. Allow students about 15 minutes to find any books or articles that make reference to physical and chemical changes. Inform students that the resources they find will be used as a “book bundle”—a collection of books on this topic to be used in the classroom for this unit.
-
Place students in groups. Each group should have a copy of the Hunt for Solutions Worksheet (S-5-1-2_Hunt for Solutions Worksheet.doc). “Discuss in your groups any questions that you may still have about physical and chemical changes. Have one person from your group write down the questions you still have. Each person in the group should be contributing.” After students have completed making their list of questions, have them brainstorm places where they would find the answers to each of those specific questions, such as their textbook, the Internet, etc. Provide students with a variety of sources (textbooks, picture books, Internet access) and allow them time to research to find the answers to their remaining questions. Students should record the answers to each of the remaining questions in the Answers section.
