Chemical+Reactions+K-2

Lesson Objectives 
 * Describe an observed event
 * Identify substances as being in the solid, liquid gaseous state
 * Observe and describe how matter can change in size, mass, color, position, quantity, time, temperature, sound, and movement.
 * Observe and describe how temperature can change the physical properties of some materials.



Engage: Activate Prior Knowledge; Generate Interest

Engage Activity: Show students pictures of [|water], [|ice], and [|steam]. Ask students to list properties of each. Make a list on the board or on chart paper. Ask students what all three have in common. (They are all forms of water)

 Place a few ice cubes in a clear container. Ask the students what they think will happen as the ice warms up. Ask them to describe what is happening to the ice as it melts. Ask them what they think will happen to the water if it is left overnight. Where do they think the water will go? Will it still be water? Tell the students that they will be describing what happens to the water as it goes from solid to liquid to gas later after they have learned more about these changes.

Provide each student with a piece of paper.(Use paper from the recycling bin to avoid unnecessary waste.) Invite them to make something out of it by cutting, folding, or rolling the paper. Ask: How has the paper changed? How is it the same? Encourage students to fold or scrunch their piece of paper into any shape they wish. Then have volunteers describe the way they changed the original flat sheet of paper.

Ask questions, such as:
 * What did you do to change the paper?
 * Describe how your paper is different from the flat piece of paper you started with.
 * Describe how your paper is same as the flat piece of paper you started with.

Explore: Allowing Students to Experience Content



Have students read the Read Alone passage [|Melting Ice]. Tell them to look for what heat does to ice and what ice does to liquid. Note that this passage is also available as an [|e-Book] for practicing readers. Then have them do the following activity.

Students will complete the Hands-On Activity [|Forms of Water].

Explain: Firm Up Understanding; Allow Students to Explain What They Know

Write the following vocabulary words on the board or chart paper: [|liquid], [|solid], [|temperature].[|gas]



Tell students:
 * A **[|solid]** is a material that keeps a fixed shape.
 * A **[|liquid]** is a material that flows, or changes shape based on the container that it is in.
 * A **[|gas]** is a material that spreads through out it's container and is often invisible
 * **[|Temperature]** is how hot or cold an object is

Display each of the interactive glossary terms above OR alternatively, have students review each term at the computer. (Rotate in teams or on lap tops if available) In their journals, students should write the definition of each term in their own words and use it in a sentence.

Elaborate: Allow Students to Apply What They Know

Show students a fresh egg and have them describe it. Encourage them to describe the parts of an egg (shell, yolk, white). Then break the eggshell and empty the innards into a bowl. Ask students to describe what they see and to determine how the physical properties of the egg have changed. Ask: How did the egg change? (The shell was cracked and the insides came out. The egg no longer has its egg shape.) Beat together the egg yolk and egg whites with a fork. Ask: Do you think the egg white and egg yolk still have all the vitamins they had when they were inside the shell? (Yes) Encourage students to discuss why, even though many of its properties are still the same, the egg can no longer return to its original form. (You may encourage students to recite the nursery rhyme about Humpty-Dumpty and then use what they have learned to explain why he could not be put together again. Show students a hard boiled egg. Ask students how the white and yolk of the egg have changed. Can this be reversed? Ask students if they know what changed the egg (heat)

Be sure to be aware of students who may be allergic to eggs so that they avoid contact.



For students needing extra challenge and as an optional extension of this task, allow the class to work cooperatively to put together the ingredients and bake a real cake. Then watch [|Magic School Bus Get’s Ready, Set, Dough]. Focus on the segment, [|Baking the Cake and the Big Escape] to discuss changes in matter. (Note: While this example goes beyond the indicators of just changing physical properties, it can be a natural extension for students who may be ready for the challenge.)

**Project Idea:** To help students apply their understanding of the physical properties of materials, you may wish to have them complete some or all of the following projects. The time required to complete each project will vary.


 * <span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;">**Junior Chef**- With adult supervision students can a recipe. Then students can make a list or write a short paragraph describing examples of how materials changed form throughout the process. For example, students can make a salad. Provide students with basic salad ingredients or pictures of whole salad ingredients, and a bowl. Have students prepare the salad by tearing up the lettuce into small pieces, cutting the cucumber into slices, etc. (Be sure to use vegetables that can be cut with a blunt knife) If using pictures, students may tear the pictures of lettuce, cucumbers, and tomatoes into small pieces. Have them put the pieces in a bowl and mix them together. Encourage students to explain how they some of the physical properties of the food items (size, shape), while retaining others (color, taste). (As with using any food products, be sure to find out if students have any allergies so that these foods are avoided.)

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 18px;">Evaluate: Check for Understanding

Evaluate Activities can occur at any point in the lesson. <span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;">Have students complete the [|Changes in Matter] selected response assessment. <span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;">Have students complete the [|Changes in Matter] constructed response assessment



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