Ready for a Change
	In this activity, students get hands-on experiences with physical and chemical changes in matter. For safety reasons, the teacher should perform the activities with assistance from the students.
FCAT Connection	Strand A: The Nature of Matter Standard 1 Benchmark: SC.A. 1.3.5
Materials	The following materials are needed for this lesson: Matches Candle Toaster Salt Table knife Lemonade powder Pitcher Paper cups (1 per student) Water Spoons Cookies (1 per group) Slice of bread Ice cubes (have extra ice on hand for the lemonade) 2 small dishes 2 small clear plastic cups Rubbing alcohol Aluminum foil Antacid tablet Vinegar Salt "Dirty" pennies
Procedures	1. Using a Venn diagram, have the students discuss examples of physical and chemical changes in matter. Remind the students that a physical change is a change in size, shape, appearance, or volume of a substance. A change of state (solid, liquid, gas) is also a physical change. Chemical changes in matter are changes that produce new substances with different characteristics. 2. Distribute the data sheets and have students work in groups to complete the data sheet while you are doing the different demonstrations. As you perform the different demonstrations, have students come up to assist with each activity. 3. To do the demonstration with the "dirty" pennies, vinegar, and salt: mix 1-tablespoon salt and 4 -tablespoons vinegar in a clear plastic cup. Drop in the dirty pennies and watch what happens. Remove the pennies, wash them off with water, and dry them with paper towels. Why does this happen? Oxygen in the air combines with the copper on the pennies to form a dull copper oxide coating. Vinegar is acetic acid. Salty is sodium chloride. When these two chemicals mix, they react to form a small amount of hydrochloric acid. This acid has the ability to remove the oxide. The result? A penny that looks like new. If you leave the pennies in the solution too long, the hydrochloric acid will etch the pennies and the suspended dirt in the solution will settle on the pennies again. 4. When all of the activities have been completed, have the students present and explain their conclusions of which of the changes are physical and which are chemical. If there are disagreements, the groups should present the reasons for their conclusions. Make sure that everyone understands the rationale behind each conclusion. 5. After you have completed all of the activities listed on the data sheet, do the two activities included with this lesson, "What A Gas!" and "A Yummy Chemical Change." Safety Precautions: Some of the activities could be hazardous for the students to do by themselves; therefore, it is suggested that the teacher do each of the demonstrations and involve the students in the activity by soliciting their assistance with each demonstration. When working with vinegar, even though it is a weak acid, you and the students should always wear safety goggles.
Assessment	The following strategies may be used to assess this lesson: 1. The completed data sheets should be evaluated using a rubric. 2. Go back to the original Venn diagram and see if any information can be added or deleted. 3. Working in groups, the students should develop a story involving both physical and chemical changes in matter. 4. Students can cut out pictures from magazines or newspapers that illustrate physical and chemical changes in matter then create a display to present to the rest of the class. The presentations can be evaluated using a rubric.
Literature Connection	Reference: 202 Science Investigations by Marjorie Frank
Attachments	Student Data Sheet What A Gas! A Yummy Chemical Change!

Rocks, Fossils or Just a Bunch of Old Bones
	In this activity, students create replacement fossils similar to the ones geologists make in the field. Background information for the activity is included at the end of this lesson plan.
FCAT Connection	Strand D: Processes that Shape the Earth Standard 1 Benchmark: SC.D.1.3.2 Strand F: Processes of Life Standard 2 Benchmark: SC.F.
Materials	The following materials will be needed for this lesson: Safety goggles Milk cartons or aluminum pie pans Clay Plastic fossils (available from various science supply companies) Shells, leaves, small plastic animal, etc. (if you do not use the plastic fossils) Talcum powder or Vaseline Toothpicks Plaster of Paris and mixing container Water Paint mixing sticks or old wooden rulers Newspapers Rags Overhead projector Transparencies of "Fossils in Geologic Time," "Earth History" and "Geologic Time Chart" Individual copies of the above information sheets
Procedures	Ask the students to discuss what they know about fossils, dinosaurs, and evolution. Do a class K-W- L to organize their responses. Leave the "L" section for an assessment activity. If using the plastic fossils, put several on each group's table for students to observe them. See if any of the students can identify any of the fossils they have. Show the students the "Fossils in Geologic Time" transparency and ask them to list the correct names for the fossils they have. Once the students have identified the fossils, spread newspapers on the table and distribute the materials for making the replacement fossils. Ask students to follow the steps listed below. Student direction sheet with diagram is attached. Put about 4-5 cm (2 in) of clay into milk a carton. To make a larger number of fossil imprints, use an aluminum pie pan instead of the milk carton. Be sure to check the amount of clay the students put in the milk cartons because they tend to use too much. Make sure the top of the clay is smooth. Put a thin coat of Vaseline on the fossils and press them into the clay. The small plastic animals can be used to make footprints across the clay. Carefully remove the fossils with toothpicks. There should be a clear print of the fossil left in the clay. This is the mold. Shake a thin film of talcum powder over the clay. Once a group has completed all of their molds, mix a container of Plaster of Paris by adding the plaster to a small amount of water until it is the consistency of whipped cream. It is best to go group by group, mixing the plaster as needed. If it remains in the mixing container too long, it will harden in the mixing container. Pour plaster over the clay in the container to a depth of about 2.5 cm (1 in). Tap the bottom of the container to remove any air bubbles in the plaster. Let the plaster harder for about 30 minutes. Be sure it is dry before continuing. If there is a limited amount of time, let the containers harden overnight. Be sure students put their names under their container. Sometimes the students can feel the warmth from the chemical reaction occurring while the plaster hardens. Gently tear the milk carton or aluminum pan away from the clay and plaster. Separate the clay from the hardened plaster.The clay can be recycled and reused. Now you have the replacement fossils, also called replacement casts. Let the students clean their casts with rags. Each group should present its replacement fossils to the rest of the students in the class. If they did a group mold in an aluminum pan, they can each say something about the process or product. Show the transparencies "Earth History" and "Geologic Time Chart" to discuss the relative dating of fossils. Be sure to point out the Jurassic Period. Most students have seen the movies and can identify with this period more than others. Linda's special tip: Students love dinosaurs. This would be a good introductory activity for a unit on dinosaurs. You may want to assign individual or group projects on different dinosaurs. There is a great deal of information available in print and on the Web to support the students' research. Safety Precautions: Be sure to wash all of the equipment used in pails of water. If any plaster goes down the drain, it will harden in the pipes and clog in the drain. Students should wear safety goggles when working with the plaster.
Assessment	The following strategies can be used to assess this lesson: Ask students to make group presentations to the class. Ask students to complete the "L" section of the original class K-W-L. Ask students to research the fossils they have and find out about each organism's habitat while it was alive. Use the attached "Fossil Research" sheet to organize this information. Working in groups, ask students to write a story about living in prehistoric times and incorporate as many of the fossils used as possible. Ask students to create a class prehistoric mural and incorporate as many of the fossils used as possible.
Literature Connection	Fossils Tell of Long Ago by Aliki How a Rock Came To Be in a Fence on a Road Near a Town by Hy Ruchlis If You Are a Hunter of Fossils by Byrd Baylor The Dinosaur Who LIved in My Backyard by B.G. Hennessy The Last Dinosaur by Jim Murphy Looking For Fossils by Dr. David Norman
Attachments	Background Information Student Information Sheet Note- Masters for transparencies will be included in attachments soon. Please check back.